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Jackson-Litteken CD, Guo W, Hogland BA, Ratliff CT, McFadden L, Fullerton MS, Voth DE, Rego ROM, Blevins JS. Development and validation of systems for genetic manipulation of the Old World tick-borne relapsing fever spirochete, Borrelia duttonii. PLoS Negl Trop Dis 2024; 18:e0012348. [PMID: 39038047 PMCID: PMC11293673 DOI: 10.1371/journal.pntd.0012348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 08/01/2024] [Accepted: 07/08/2024] [Indexed: 07/24/2024] Open
Abstract
Relapsing fever (RF), a vector-borne disease caused by Borrelia spp., is characterized by recurring febrile episodes due to repeated bouts of bacteremia. RF spirochetes can be geographically and phylogenetically divided into two distinct groups; Old World RF Borrelia (found in Africa, Asia, and Europe) and New World RF Borrelia (found in the Americas). While RF is a rarely reported disease in the Americas, RF is prevalent in endemic parts of Africa. Despite phylogenetic differences between Old World and New World RF Borrelia and higher incidence of disease associated with Old World RF spirochete infection, genetic manipulation has only been described in New World RF bacteria. Herein, we report the generation of genetic tools for use in the Old World RF spirochete, Borrelia duttonii. We describe methods for transformation and establish shuttle vector- and integration-based approaches for genetic complementation, creating green fluorescent protein (gfp)-expressing B. duttonii strains as a proof of principle. Allelic exchange mutagenesis was also used to inactivate a homolog of the Borrelia burgdorferi p66 gene, which encodes an important virulence factor, in B. duttonii and demonstrate that this mutant was attenuated in a murine model of RF. Finally, the B. duttonii p66 mutant was complemented using shuttle vector- and cis integration-based approaches. As expected, complemented p66 mutant strains were fully infectious, confirming that P66 is required for optimal mammalian infection. The genetic tools and techniques reported herein represent an important advancement in the study of RF Borrelia that allows for future characterization of virulence determinants and colonization factors important for the enzootic cycle of Old World RF spirochetes.
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Affiliation(s)
- Clay D. Jackson-Litteken
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Wanfeng Guo
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Brandon A. Hogland
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - C. Tyler Ratliff
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - LeAnn McFadden
- Department of Biology, University of Arkansas at Little Rock, Little Rock, Arkansas, United States of America
| | - Marissa S. Fullerton
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Daniel E. Voth
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Ryan O. M. Rego
- Institute of Parasitology, Biology Centre CAS, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Jon S. Blevins
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
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Tan X, Castellanos M, Chaconas G. Choreography of Lyme Disease Spirochete Adhesins To Promote Vascular Escape. Microbiol Spectr 2023; 11:e0125423. [PMID: 37255427 PMCID: PMC10434219 DOI: 10.1128/spectrum.01254-23] [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: 03/23/2023] [Accepted: 05/12/2023] [Indexed: 06/01/2023] Open
Abstract
The Lyme disease spirochete Borrelia burgdorferi sensu lato can cause a multitude of clinical manifestations because of its ability to disseminate into any organ system via migration through soft tissue, the lymphatic system, and the circulatory system. The latter is believed to constitute the predominant pathway for dissemination to distal sites from the inoculating tick bite. In spite of its importance, the hematogenous dissemination process remains largely uncharacterized, particularly due to difficulties studying this process in a living host and the lack of an in vitro system that recapitulates animal infection. In the current work, we provide the first information regarding the stage of the vascular transmigration pathway where three important adhesins function during invasion of mouse knee joint peripheral tissue from postcapillary venules. Using intravital imaging coupled with genetic experiments employing sequential double infection, we show a complex temporal choreography of P66, decorin binding proteins (DbpA/B), and outer surface protein C (OspC) at discrete steps along the pathway of vascular escape, underscoring the importance of B. burgdorferi adhesins in hematogenous dissemination in the mouse knee joint and the complexity of vascular transmigration by a disseminating pathogen. IMPORTANCE Lyme disease is caused by the spirochete Borrelia burgdorferi, which is transmitted by a bite from an infected tick. Disease development involves a complex series of host-pathogen interactions as well as dissemination of the infecting organisms to sites distal to the original tick bite. The predominant pathway for this is believed to be hematogenous dissemination. The mechanism by which the spirochetes escape circulation is unknown. Here, using intravital microscopy, where the Lyme spirochete can be observed in a living mouse, we have studied the stage in the vascular escape process where each of three surface adhesins functions to facilitate escape of the spirochete from postcapillary venules to invade mouse knee joint peripheral tissue. A complex pattern of involvement at various locations in the multistage process is described using a unique experimental approach that is applicable to other disseminating pathogens.
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Affiliation(s)
- Xi Tan
- Department of Biochemistry & Molecular Biology, University of Calgary, Calgary, Alberta, Canada
| | - Mildred Castellanos
- Department of Biochemistry & Molecular Biology, University of Calgary, Calgary, Alberta, Canada
| | - George Chaconas
- Department of Biochemistry & Molecular Biology, University of Calgary, Calgary, Alberta, Canada
- Department of Microbiology, Immunology & Infectious Diseases, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
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Golidonova K, Korenberg E, Krupinskaya E, Matrosova V, Gintsburg A. Allelic Variants of P66 Gene in Borrelia bavariensis Isolates from Patients with Ixodid Tick-Borne Borreliosis. Microorganisms 2022; 10:microorganisms10122509. [PMID: 36557762 PMCID: PMC9782215 DOI: 10.3390/microorganisms10122509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/09/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
Protein P66 is one of the crucial virulence factors of Borrelia, inducing the production of specific antibodies in patients with ixodid tick-borne borreliosis (ITBB). Various species of Borrelia are characterized by genetic variability of the surface-exposed loop of P66. However, little is known about this variability in Borrelia bavariensis. Here we describe the variability of the nucleotide sequences of P66 gene locus in isolates of B. bavariensis. Analysis of nucleotide sequences of P66 in 27 isolates of B. bavariensis from ITBB patients revealed three allelic variants of this gene. The alignment score of amino acid sequences in the isolates showed amino acid replacements in various positions confirming the presence of three allelic variants. Two of them are characteristic only for some isolates of B. bavariensis of the Eurasian gene pool from various parts of the geographic ranges of B. bavariensis from various samples. At least three allelic variants of P66 B. bavariensis have been identified, which have different amino acid expression, occur with different frequency in ITBB patients and, presumably, can have different effects on the course of the infection.
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Affiliation(s)
- Kristina Golidonova
- N. F. Gamaleya National Research Centre for Epidemiology and Microbiology, 123098 Moscow, Russia
- Correspondence: ; Tel.: +7-985-337-01-85
| | - Eduard Korenberg
- N. F. Gamaleya National Research Centre for Epidemiology and Microbiology, 123098 Moscow, Russia
| | - Ekaterina Krupinskaya
- N. F. Gamaleya National Research Centre for Epidemiology and Microbiology, 123098 Moscow, Russia
| | - Vera Matrosova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Alexander Gintsburg
- N. F. Gamaleya National Research Centre for Epidemiology and Microbiology, 123098 Moscow, Russia
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Abstract
The Borrelia spp. are tick-borne pathogenic spirochetes that include the agents of Lyme disease and relapsing fever. As part of their life cycle, the spirochetes traffic between the tick vector and the vertebrate host, which requires significant physiological changes and remodeling of their outer membranes and proteome. This crucial proteome resculpting is carried out by a diverse set of proteases, adaptor proteins, and related chaperones. Despite its small genome, Borrelia burgdorferi has dedicated a large percentage of its genome to proteolysis, including a full complement of ATP-dependent proteases. Energy-driven proteolysis appears to be an important physiological feature of this dual-life-cycle bacterium. The proteolytic arsenal of Borrelia is strategically deployed for disposal of proteins no longer required as they move from one stage to another or are transferred from one host to another. Likewise, the Borrelia spp. are systemic organisms that need to break down and move through host tissues and barriers, and so their unique proteolytic resources, both endogenous and borrowed, make movement more feasible. Both the Lyme disease and relapsing fever Borrelia spp. bind plasminogen as well as numerous components of the mammalian plasminogen-activating system. This recruitment capacity endows the spirochetes with a borrowed proteolytic competency that can lead to increased invasiveness.
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Coburn J, Garcia B, Hu LT, Jewett MW, Kraiczy P, Norris SJ, Skare J. Lyme Disease Pathogenesis. Curr Issues Mol Biol 2020; 42:473-518. [PMID: 33353871 DOI: 10.21775/cimb.042.473] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Lyme disease Borrelia are obligately parasitic, tick- transmitted, invasive, persistent bacterial pathogens that cause disease in humans and non-reservoir vertebrates primarily through the induction of inflammation. During transmission from the infected tick, the bacteria undergo significant changes in gene expression, resulting in adaptation to the mammalian environment. The organisms multiply and spread locally and induce inflammatory responses that, in humans, result in clinical signs and symptoms. Borrelia virulence involves a multiplicity of mechanisms for dissemination and colonization of multiple tissues and evasion of host immune responses. Most of the tissue damage, which is seen in non-reservoir hosts, appears to result from host inflammatory reactions, despite the low numbers of bacteria in affected sites. This host response to the Lyme disease Borrelia can cause neurologic, cardiovascular, arthritic, and dermatologic manifestations during the disseminated and persistent stages of infection. The mechanisms by which a paucity of organisms (in comparison to many other infectious diseases) can cause varied and in some cases profound inflammation and symptoms remains mysterious but are the subjects of diverse ongoing investigations. In this review, we provide an overview of virulence mechanisms and determinants for which roles have been demonstrated in vivo, primarily in mouse models of infection.
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Affiliation(s)
- Jenifer Coburn
- Center For Infectious Disease Research, Medical College of Wisconsin, 8701 Watertown Plank Rd., TBRC C3980, Milwaukee, WI 53226, USA
| | - Brandon Garcia
- Department of Microbiology and Immunology, East Carolina University, Brody School of Medicine, Greenville, NC 27858, USA
| | - Linden T Hu
- Department of Molecular Biology and Microbiology, Vice Dean of Research, Tufts University School of Medicine, 136 Harrison Ave., Boston, MA 02111, USA
| | - Mollie W Jewett
- Immunity and Pathogenesis Division Head, Burnett School of Biomedical Sciences, University of Central Florida College of Medicine, 6900 Lake Nona Blvd. Orlando, FL 32827, USA
| | - Peter Kraiczy
- Institute of Medical Microbiology and Infection Control, University Hospital Frankfurt, Goethe University Frankfurt, Paul-Ehrlich-Str. 40, 60596 Frankfurt, Germany
| | - Steven J Norris
- Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, P.O. Box 20708, Houston, TX 77225, USA
| | - Jon Skare
- Professor and Associate Head, Texas A and M University, 8447 Riverside Pkwy, Bryan, TX 77807, USA
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Structural and Biomolecular Analyses of Borrelia burgdorferi BmpD Reveal a Substrate-Binding Protein of an ABC-Type Nucleoside Transporter Family. Infect Immun 2020; 88:IAI.00962-19. [PMID: 31988175 PMCID: PMC7093131 DOI: 10.1128/iai.00962-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 01/23/2020] [Indexed: 02/08/2023] Open
Abstract
Borrelia burgdorferisensu lato, the causative agent of tick-borne Lyme borreliosis (LB), has a limited metabolic capacity and needs to acquire nutrients, such as amino acids, fatty acids, and nucleic acids, from the host environment. Using X-ray crystallography, liquid chromatography-mass spectrometry, microscale thermophoresis, and cellular localization studies, we show that basic membrane protein D (BmpD) is a periplasmic substrate-binding protein of an ABC transporter system binding to purine nucleosides. Borrelia burgdorferisensu lato, the causative agent of tick-borne Lyme borreliosis (LB), has a limited metabolic capacity and needs to acquire nutrients, such as amino acids, fatty acids, and nucleic acids, from the host environment. Using X-ray crystallography, liquid chromatography-mass spectrometry, microscale thermophoresis, and cellular localization studies, we show that basic membrane protein D (BmpD) is a periplasmic substrate-binding protein of an ABC transporter system binding to purine nucleosides. Nucleosides are essential for bacterial survival in the host organism, and these studies suggest a key role for BmpD in the purine salvage pathway of B. burgdorferi sensu lato. Because B. burgdorferisensu lato lacks the enzymes required for de novo purine synthesis, BmpD may play a vital role in ensuring access to the purines needed to sustain an infection in the host. Furthermore, we show that, although human LB patients develop anti-BmpD antibodies, immunization of mice with BmpD does not confer protection against B. burgdorferi sensu lato infection.
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Vechtova P, Sterbova J, Sterba J, Vancova M, Rego ROM, Selinger M, Strnad M, Golovchenko M, Rudenko N, Grubhoffer L. A bite so sweet: the glycobiology interface of tick-host-pathogen interactions. Parasit Vectors 2018; 11:594. [PMID: 30428923 PMCID: PMC6236881 DOI: 10.1186/s13071-018-3062-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 08/14/2018] [Indexed: 11/10/2022] Open
Abstract
Vector-borne diseases constitute 17% of all infectious diseases in the world; among the blood-feeding arthropods, ticks transmit the highest number of pathogens. Understanding the interactions between the tick vector, the mammalian host and the pathogens circulating between them is the basis for the successful development of vaccines against ticks or the tick-transmitted pathogens as well as for the development of specific treatments against tick-borne infections. A lot of effort has been put into transcriptomic and proteomic analyses; however, the protein-carbohydrate interactions and the overall glycobiology of ticks and tick-borne pathogens has not been given the importance or priority deserved. Novel (bio)analytical techniques and their availability have immensely increased the possibilities in glycobiology research and thus novel information in the glycobiology of ticks and tick-borne pathogens is being generated at a faster pace each year. This review brings a comprehensive summary of the knowledge on both the glycosylated proteins and the glycan-binding proteins of the ticks as well as the tick-transmitted pathogens, with emphasis on the interactions allowing the infection of both the ticks and the hosts by various bacteria and tick-borne encephalitis virus.
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Affiliation(s)
- Pavlina Vechtova
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, CZ-37005, České Budějovice, Czech Republic. .,Faculty of Science, University of South Bohemia, Branišovská 1760, CZ-37005, České Budějovice, Czech Republic.
| | - Jarmila Sterbova
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, CZ-37005, České Budějovice, Czech Republic.,Faculty of Science, University of South Bohemia, Branišovská 1760, CZ-37005, České Budějovice, Czech Republic
| | - Jan Sterba
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, CZ-37005, České Budějovice, Czech Republic.,Faculty of Science, University of South Bohemia, Branišovská 1760, CZ-37005, České Budějovice, Czech Republic
| | - Marie Vancova
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, CZ-37005, České Budějovice, Czech Republic.,Faculty of Science, University of South Bohemia, Branišovská 1760, CZ-37005, České Budějovice, Czech Republic
| | - Ryan O M Rego
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, CZ-37005, České Budějovice, Czech Republic.,Faculty of Science, University of South Bohemia, Branišovská 1760, CZ-37005, České Budějovice, Czech Republic
| | - Martin Selinger
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, CZ-37005, České Budějovice, Czech Republic.,Faculty of Science, University of South Bohemia, Branišovská 1760, CZ-37005, České Budějovice, Czech Republic
| | - Martin Strnad
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, CZ-37005, České Budějovice, Czech Republic.,Faculty of Science, University of South Bohemia, Branišovská 1760, CZ-37005, České Budějovice, Czech Republic
| | - Maryna Golovchenko
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, CZ-37005, České Budějovice, Czech Republic
| | - Nataliia Rudenko
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, CZ-37005, České Budějovice, Czech Republic
| | - Libor Grubhoffer
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, CZ-37005, České Budějovice, Czech Republic.,Faculty of Science, University of South Bohemia, Branišovská 1760, CZ-37005, České Budějovice, Czech Republic
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8
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Bergström S, Normark J. Microbiological features distinguishing Lyme disease and relapsing fever spirochetes. Wien Klin Wochenschr 2018; 130:484-490. [PMID: 30074091 PMCID: PMC6096528 DOI: 10.1007/s00508-018-1368-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 07/13/2018] [Indexed: 12/13/2022]
Abstract
The recent proposal of splitting the genus Borrelia into two genera in the newly formed family of Borreliaceae, i. e. Borrelia and Borreliella has motivated us to reflect upon how these organisms has been characterized and differentiated. This article therefore aims to take a closer look on the biology and virulence attributes of the two suggested genera, i. e. those causing Lyme borreliosis and relapsing fever borreliosis. Both genera have much in common with similar infection biological features. They are both characterized as bacterial zoonoses, transmitted by hematophagous arthropods with almost identical microbiological appearance. Nevertheless, a closer look at the genotypic and phenotypic characteristics clearly reveals several differences that might motivate the suggested split. On the other hand, a change of this well-established classification within the genus Borrelia might impose an economical burden as well as a great confusion in society, including medical and scientific societies as well as the general population.
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Affiliation(s)
- Sven Bergström
- Department of Molecular Biology, Umeå University, 6K och 6L, Sjukhusområdet, 901 87, Umeå, Sweden. .,Umeå Center for Microbial Research, Umeå University, Umeå, Sweden. .,Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden.
| | - Johan Normark
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden.,Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
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9
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Abstract
Borrelia burgdorferi HtrA (HtrABb) is a serine protease that targets damaged or improperly folded proteins. In our previous studies, HtrABb specifically degraded basic membrane protein BmpD, chemotaxis phosphatase CheX, and outer membrane protein P66. In addition, HtrABb degrades virulence factor BB0323 and components of the extracellular matrix fibronectin and aggrecan. A proteomics-based analysis (two-dimensional difference gel electrophoresis [2-D DIGE], liquid chromatography-mass spectrometry [LC-MS]) of an HtrABb-overexpressing strain of B. burgdorferi (A3HtrAOE) revealed that protein levels of P66 were reduced in comparison to wild-type B. burgdorferi, confirming its status as an HtrABb substrate. Hbb, a P66-DNA-binding transcription factor, was specifically degraded by HtrABb, providing supportive evidence for a role for both in the regulation of P66. A3HtrAOE exhibited reduced motility in swarm assays, a possible link between overabundance of HtrABb and its enzymatic specificity for P66. However, the ΔP66 strain did not have reduced motility in the swarm assays, negating a role for this protein. The proteomics analyses also identified three enzymes of the glycolytic pathway, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), glycerol-3-phosphate dehydrogenase (GPDH), and glycerol kinase (GK), and one enzyme involved in carbohydrate metabolism, diphosphate-fructose-6-phosphate 1-phosphotransferase, which were reduced in A3HtrAOE. Consistent with its reduced protein levels of these glycolytic enzymes, A3HtrAOE was also deficient in production of pyruvate. We propose a model for a role for HtrABb in contributing to a decrease in metabolic activity of B. burgdorferi. Being a vector-borne bacterium, B. burgdorferi must remodel its protein content as it transfers from tick to mammal. Proteolysis is a mechanism whereby remodeling can be accomplished. HtrABb degrades a number of proteins whose disappearance may help in preparing this organism for a stage of low metabolic activity.
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Hyde JA. Borrelia burgdorferi Keeps Moving and Carries on: A Review of Borrelial Dissemination and Invasion. Front Immunol 2017; 8:114. [PMID: 28270812 PMCID: PMC5318424 DOI: 10.3389/fimmu.2017.00114] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 01/25/2017] [Indexed: 12/21/2022] Open
Abstract
Borrelia burgdorferi is the etiological agent of Lyme disease, a multisystemic, multistage, inflammatory infection resulting in patients experiencing cardiac, neurological, and arthritic complications when not treated with antibiotics shortly after exposure. The spirochetal bacterium transmits through the Ixodes vector colonizing the dermis of a mammalian host prior to hematogenous dissemination and invasion of distal tissues all the while combating the immune response as it traverses through its pathogenic lifecycle. The innate immune response controls the borrelial burden in the dermis, but is unable to clear the infection and thereby prevent progression of disease. Dissemination in the mammalian host requires temporal regulation of virulence determinants to allow for vascular interactions, invasion, and colonization of distal tissues. Virulence determinants and/or adhesins are highly heterogenetic among environmental B. burgdorferi strains with particular genotypes being associated with the ability to disseminate to specific tissues and the severity of disease, but fail to generate cross-protective immunity between borrelial strains. The unique motility of B. burgdorferi rendered by the endoflagella serves a vital function for dissemination and protection from immune recognition. Progress has been made toward understanding the chemotactic regulation coordinating the activity of the two polar localized flagellar motors and their role in borrelial virulence, but this regulation is not yet fully understood. Distinct states of motility allow for dynamic interactions between several B. burgdorferi adhesins and host targets that play roles in transendothelial migration. Transmigration across endothelial and blood-brain barriers allows for the invasion of tissues and elicits localized immune responses. The invasive nature of B. burgdorferi is lacking in proactive mechanisms to modulate disease, such as secretion systems and toxins, but recent work has shown degradation of host extracellular matrices by B. burgdorferi contributes to the invasive capabilities of the pathogen. Additionally, B. burgdorferi may use invasion of eukaryotic cells for immune evasion and protection against environmental stresses. This review provides an overview of B. burgdorferi mechanisms for dissemination and invasion in the mammalian host, which are essential for pathogenesis and the development of persistent infection.
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Affiliation(s)
- Jenny A Hyde
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M Health Science Center , Bryan, TX , USA
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11
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Kenedy MR, Scott EJ, Shrestha B, Anand A, Iqbal H, Radolf JD, Dyer DW, Akins DR. Consensus computational network analysis for identifying candidate outer membrane proteins from Borrelia spirochetes. BMC Microbiol 2016; 16:141. [PMID: 27400788 PMCID: PMC4939628 DOI: 10.1186/s12866-016-0762-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 07/02/2016] [Indexed: 01/15/2023] Open
Abstract
Background Similar to Gram-negative organisms, Borrelia spirochetes are dual-membrane organisms with both an inner and outer membrane. Although the outer membrane contains integral membrane proteins, few of the borrelial outer membrane proteins (OMPs) have been identified and characterized to date. Therefore, we utilized a consensus computational network analysis to identify novel borrelial OMPs. Results Using a series of computer-based algorithms, we selected all protein-encoding sequences predicted to be OM-localized and/or to form β-barrels in the borrelial OM. Using this system, we identified 41 potential OMPs from B. burgdorferi and characterized three (BB0838, BB0405, and BB0406) to confirm that our computer-based methodology did, in fact, identify borrelial OMPs. Triton X-114 phase partitioning revealed that BB0838 is found in the detergent phase, which would be expected of a membrane protein. Proteolysis assays indicate that BB0838 is partially sensitive to both proteinase K and trypsin, further indicating that BB0838 is surface-exposed. Consistent with a prior study, we also confirmed that BB0405 is surface-exposed and associates with the borrelial OM. Furthermore, we have shown that BB0406, the product of a co-transcribed downstream gene, also encodes a novel, previously uncharacterized borrelial OMP. Interestingly, while BB0406 has several physicochemical properties consistent with it being an OMP, it was found to be resistant to surface proteolysis. Consistent with BB0405 and BB0406 being OMPs, both were found to be capable of incorporating into liposomes and exhibit pore-forming activity, suggesting that both proteins are porins. Lastly, we expanded our computational analysis to identify OMPs from other borrelial organisms, including both Lyme disease and relapsing fever spirochetes. Conclusions Using a consensus computer algorithm, we generated a list of candidate OMPs for both Lyme disease and relapsing fever spirochetes and determined that three of the predicted B. burgdorferi proteins identified were indeed novel borrelial OMPs. The combined studies have identified putative spirochetal OMPs that can now be examined for their roles in virulence, physiology, and disease pathogenesis. Importantly, the studies described in this report provide a framework by which OMPs from any human pathogen with a diderm ultrastructure could be cataloged to identify novel virulence factors and vaccine candidates. Electronic supplementary material The online version of this article (doi:10.1186/s12866-016-0762-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Melisha R Kenedy
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, 73104, USA
| | - Edgar J Scott
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, 73104, USA
| | - Binu Shrestha
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, 73104, USA
| | - Arvind Anand
- Department of Medicine, University of Connecticut Health Center, Farmington, Connecticut, 06030, USA
| | - Henna Iqbal
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, 73104, USA
| | - Justin D Radolf
- Department of Medicine, University of Connecticut Health Center, Farmington, Connecticut, 06030, USA.,Department of Pediatrics, University of Connecticut Health Center, Farmington, Connecticut, 06030, USA.,Department of Genetics and Genomic Science, University of Connecticut Health Center, Farmington, Connecticut, 06030, USA.,Department of Immunology, University of Connecticut Health Center, Farmington, Connecticut, 06030, USA.,Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, Connecticut, 06030, USA
| | - David W Dyer
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, 73104, USA
| | - Darrin R Akins
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, 73104, USA.
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12
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Merlos A, Rodríguez P, Bárcena-Uribarri I, Winterhalter M, Benz R, Vinuesa T, Moya JA, Viñas M. Toxins Secreted by Bacillus Isolated from Lung Adenocarcinomas Favor the Penetration of Toxic Substances. Front Microbiol 2015; 6:1301. [PMID: 26635767 PMCID: PMC4655230 DOI: 10.3389/fmicb.2015.01301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 11/06/2015] [Indexed: 01/17/2023] Open
Abstract
The aim was to explore the eventual role of bacteria in the induction of lung cancer by smoking habits. Viable bacteria closely related to the genus Bacillus were detected at high frequencies in lung-cancer biopsies. Similar, if not identical, microbes were isolated from cigarettes and in smog. Bacteria present in cigarettes could be transferred to a physiological solution via a "smoker" device that mimicked their potential transfer during smoking those bacteria produce exotoxins able to open transmembrane pores. These channels can be used as a way to penetrate cells of benzopyrenes and other toxic substances present in tobacco products. We hypothesize that Bacillaceae present in tobacco play a key role in the development of lung cancer.
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Affiliation(s)
- Alexandra Merlos
- Molecular Microbiology and Antibiotics, Department of Pathology and Experimental Therapeutics, Medical School, University of Barcelona Barcelona, Spain
| | - Pau Rodríguez
- Department of Thoracic Surgery, Hospital Universitari de Bellvitge, University of Barcelona-IDIBELL-HUB Barcelona, Spain
| | | | | | | | - Teresa Vinuesa
- Molecular Microbiology and Antibiotics, Department of Pathology and Experimental Therapeutics, Medical School, University of Barcelona Barcelona, Spain
| | - Juan A Moya
- Department of Thoracic Surgery, Hospital Universitari de Bellvitge, University of Barcelona-IDIBELL-HUB Barcelona, Spain
| | - Miguel Viñas
- Molecular Microbiology and Antibiotics, Department of Pathology and Experimental Therapeutics, Medical School, University of Barcelona Barcelona, Spain ; Cooperativa de Ensino Superior Politécnico e Universitário, IINFACTS Gandra, Portugal
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13
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Coleman JL, Toledo A, Benach JL. Borrelia burgdorferi HtrA: evidence for twofold proteolysis of outer membrane protein p66. Mol Microbiol 2015; 99:135-50. [PMID: 26370492 DOI: 10.1111/mmi.13221] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/11/2015] [Indexed: 12/20/2022]
Abstract
In prokaryotes, members of the High Temperature Requirement A (HtrA) family of serine proteases function in the periplasm to degrade damaged or improperly folded membrane proteins. Borrelia burgdorferi, the agent of Lyme disease, codes for a single HtrA homolog. Two-dimensional electrophoresis analysis of B. burgdorferi B31A3 and a strain that overexpresses HtrA (A3HtrAOE) identified a downregulated protein in A3HtrAOE with a mass, pI and MALDI-TOF spectrum consistent with outer membrane protein p66. P66 and HtrA from cellular lysates partitioned into detergent-resistant membranes, which contain cholesterol-glycolipid-rich membrane regions known as lipid rafts, suggesting that HtrA and p66 may reside together in lipid rafts also. This agrees with previous work from our laboratory, which showed that HtrA and p66 are constituents of B. burgdorferi outer membrane vesicles. HtrA degraded p66 in vitro and A3HtrAOE expressed reduced levels of p66 in vivo. Fluorescence confocal microscopy revealed that HtrA and p66 colocalize in the membrane. The association of HtrA and p66 establishes that they could interact efficiently and their protease/substrate relationship provides functional relevance to this interaction. A3HtrAOE also showed reduced levels of p66 transcript in comparison with wild-type B31A3, indicating that HtrA-mediated regulation of p66 may occur at multiple levels.
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Affiliation(s)
- James L Coleman
- New York State Department of Health, Stony Brook University, Stony Brook, NY, USA.,Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, USA
| | - Alvaro Toledo
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, USA
| | - Jorge L Benach
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, USA
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14
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Abstract
Relapsing fever borreliae were notorious and feared infectious agents that earned their place in history through their devastating impact as causes of both epidemic and endemic infection. They are now considered more as an oddity, and their burden of infection is largely overshadowed by other infections such as malaria, which presents in a similar clinical way. Despite this, they remain the most common bacterial infection in some developing countries. Transmitted by soft ticks or lice, these fascinating spirochetes have evolved a myriad of mechanisms to survive within their diverse environments.
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Affiliation(s)
- Sally J Cutler
- School of Health, Sport and Bioscience, University of East London, London E15 4LZ, UK.
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15
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Cross-Reactive Epitopes in Borrelia burgdorferi p66. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2015; 22:840-3. [PMID: 25972406 DOI: 10.1128/cvi.00217-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 05/08/2015] [Indexed: 11/20/2022]
Abstract
Epitope mapping of the p66 outer membrane protein of Borrelia burgdorferi revealed that the protein contains numerous cross-reactive linear epitopes recognized by serum antibody in the majority of individuals tested, regardless of Lyme disease history, limiting the usefulness of this antigen in Lyme disease serodiagnostic assays.
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16
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Evaluation of cell binding activities of Leptospira ECM adhesins. PLoS Negl Trop Dis 2015; 9:e0003712. [PMID: 25875373 PMCID: PMC4397020 DOI: 10.1371/journal.pntd.0003712] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 03/19/2015] [Indexed: 12/02/2022] Open
Abstract
Pathogenic spirochetes of the genus Leptospira are the causative agents of leptospirosis, a zoonotic infection that occurs globally. The bacteria colonize the renal proximal tubules of many animals and are shed in the urine. Contact with the urine, or with water contaminated with the urine of infected animals can cause infection of new host animals, including humans. Mechanisms of colonization of the proximal tubule and other tissues are not known, but specific interactions between bacterial adhesins and host substrates are likely to be critical in this process. Several extracellular matrix (ECM) adhesins have been previously identified, but more recently, it has been shown that Leptospira bind more efficiently to cells than ECM. In this work, recombinant forms of five putative Leptospira ECM adhesins, namely LipL32, Loa22, OmpL1, p31/LipL45, and LenA were evaluated for binding to cells as well as an expanded variety of ECM components. Reproducible and significant adhesin activity was demonstrated only for OmpL1, which bound to both mammalian cell lines tested and to glycosaminoglycans (GAGs). While determination of biologically significant bacterial adhesion activity will require generation of site-directed mutant strains, our results suggest that OmpL1 is a strong candidate for future evaluation regarding the roles of the adhesin activity of the protein during L. interrogans infection. Leptospirosis is the most widespread zoonotic infection in the world and represents a major public health problem, especially in tropical climates. The processes by which some Leptospira species cause infection, disease, and colonization of carrier animals remains poorly understood. Specific binding of Leptospira molecules and host molecules are likely important for infection and colonization. To identify Leptospira molecules that mediate attachment to host substrates, prior studies have evaluated Leptospira membrane proteins for binding to extracellular matrix (ECM) proteins. More recent data, however, show that Leptospira bind more efficiently to cells than to ECM. In search of adhesins mediating the latter activity, our study evaluated the direct cell binding activity of recombinant forms of a group of previously reported Leptospira ECM adhesins. Only one of these proteins, OmpL1, demonstrated reproducible direct cell binding activity. Further work will focus on identification of the mammalian receptor for OmpL1 and determining the biological significance of this activity during infection.
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17
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Ristow LC, Bonde M, Lin YP, Sato H, Curtis M, Wesley E, Hahn BL, Fang J, Wilcox DA, Leong JM, Bergström S, Coburn J. Integrin binding by Borrelia burgdorferi P66 facilitates dissemination but is not required for infectivity. Cell Microbiol 2015; 17:1021-36. [PMID: 25604835 PMCID: PMC4478124 DOI: 10.1111/cmi.12418] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 01/13/2015] [Accepted: 01/15/2015] [Indexed: 12/20/2022]
Abstract
P66, a Borrelia burgdorferi surface protein with porin and integrin‐binding activities, is essential for murine infection. The role of P66 integrin‐binding activity in B. burgdorferi infection was investigated and found to affect transendothelial migration. The role of integrin binding, specifically, was tested by mutation of two amino acids (D205A,D207A) or deletion of seven amino acids (Del202–208). Neither change affected surface localization or channel‐forming activity of P66, but both significantly reduced binding to αvβ3. Integrin‐binding deficient B. burgdorferi strains caused disseminated infection in mice at 4 weeks post‐subcutaneous inoculation, but bacterial burdens were significantly reduced in some tissues. Following intravenous inoculation, the Del202–208 bacteria were below the limit of detection in all tissues assessed at 2 weeks post‐inoculation, but bacterial burdens recovered to wild‐type levels at 4 weeks post‐inoculation. The delay in tissue colonization correlated with reduced migration of the Del202–208 strains across microvascular endothelial cells, similar to Δp66 bacteria. These results indicate that integrin binding by P66 is important to efficient dissemination of B. burgdorferi, which is critical to its ability to cause disease manifestations in incidental hosts and to its maintenance in the enzootic cycle.
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Affiliation(s)
- Laura C Ristow
- Graduate Program in Microbiology, Immunology, and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI, USA.,Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Mari Bonde
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Yi-Pin Lin
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA
| | - Hiromi Sato
- Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, WI, USA.,Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Michael Curtis
- Graduate Program in Microbiology, Immunology, and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI, USA.,Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Erin Wesley
- Graduate Program in Microbiology, Immunology, and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Beth L Hahn
- Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, WI, USA.,Division of Infectious Diseases, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Juan Fang
- Department of Pediatrics, MACC Fund Research Center, Children's Research Institute, Children's Hospital of Wisconsin and Medical College of Wisconsin, Milwaukee, WI, USA
| | - David A Wilcox
- Department of Pediatrics, MACC Fund Research Center, Children's Research Institute, Children's Hospital of Wisconsin and Medical College of Wisconsin, Milwaukee, WI, USA
| | - John M Leong
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA
| | - Sven Bergström
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Jenifer Coburn
- Graduate Program in Microbiology, Immunology, and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI, USA.,Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, WI, USA.,Division of Infectious Diseases, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
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18
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Bárcena-Uribarri I, Thein M, Barbot M, Sans-Serramitjana E, Bonde M, Mentele R, Lottspeich F, Bergström S, Benz R. Study of the protein complex, pore diameter, and pore-forming activity of the Borrelia burgdorferi P13 porin. J Biol Chem 2014; 289:18614-24. [PMID: 24825899 DOI: 10.1074/jbc.m113.539528] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
P13 is one of the major outer membrane proteins of Borrelia burgdorferi. Previous studies described P13 as a porin. In the present study some structure and function aspects of P13 were studied. P13 showed according to lipid bilayer studies a channel-forming activity of 0.6 nanosiemens in 1 m KCl. Single channel and selectivity measurements demonstrated that P13 had no preference for either cations or anions and showed no voltage-gating up to ±100 mV. Blue native polyacrylamide gel electrophoresis was used to isolate and characterize the P13 protein complex in its native state. The complex had a high molecular mass of about 300 kDa and was only composed of P13 monomers. The channel size was investigated using non-electrolytes revealing an apparent diameter of about 1.4 nm with a 400-Da molecular mass cut-off. Multichannel titrations with different substrates reinforced the idea that P13 forms a general diffusion channel. The identity of P13 within the complex was confirmed by second dimension SDS-PAGE, Western blotting, mass spectrometry, and the use of a p13 deletion mutant strain. The results suggested that P13 is the protein responsible for the 0.6-nanosiemens pore-forming activity in the outer membrane of B. burgdorferi.
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Affiliation(s)
- Iván Bárcena-Uribarri
- From the Rudolf-Virchow-Center, Deutsche Forschungsgemeinschaft Research Center for Experimental Biomedicine, University of Würzburg, Versbacher Strasse 9, D-97078 Würzburg, Germany, School of Engineering and Science, Jacobs University Bremen, Campusring 1, D-28759 Bremen, Germany,
| | - Marcus Thein
- From the Rudolf-Virchow-Center, Deutsche Forschungsgemeinschaft Research Center for Experimental Biomedicine, University of Würzburg, Versbacher Strasse 9, D-97078 Würzburg, Germany
| | - Mariam Barbot
- From the Rudolf-Virchow-Center, Deutsche Forschungsgemeinschaft Research Center for Experimental Biomedicine, University of Würzburg, Versbacher Strasse 9, D-97078 Würzburg, Germany
| | - Eulalia Sans-Serramitjana
- From the Rudolf-Virchow-Center, Deutsche Forschungsgemeinschaft Research Center for Experimental Biomedicine, University of Würzburg, Versbacher Strasse 9, D-97078 Würzburg, Germany
| | - Mari Bonde
- Department of Molecular Biology, Umeå University, S-90187 Umeå, Sweden, and
| | - Reinhard Mentele
- Max-Planck Institute of Biochemistry, Protein Analysis Department, Am Klopferspitz 18, D-82152 Martinsried, Germany
| | - Friedrich Lottspeich
- Max-Planck Institute of Biochemistry, Protein Analysis Department, Am Klopferspitz 18, D-82152 Martinsried, Germany
| | - Sven Bergström
- Department of Molecular Biology, Umeå University, S-90187 Umeå, Sweden, and
| | - Roland Benz
- From the Rudolf-Virchow-Center, Deutsche Forschungsgemeinschaft Research Center for Experimental Biomedicine, University of Würzburg, Versbacher Strasse 9, D-97078 Würzburg, Germany, School of Engineering and Science, Jacobs University Bremen, Campusring 1, D-28759 Bremen, Germany
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19
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Structural modeling and physicochemical characterization provide evidence that P66 forms a β-barrel in the Borrelia burgdorferi outer membrane. J Bacteriol 2013; 196:859-72. [PMID: 24317399 DOI: 10.1128/jb.01236-13] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The Borrelia burgdorferi outer membrane (OM) contains numerous surface-exposed lipoproteins but a relatively low density of integral OM proteins (OMPs). Few membrane-spanning OMPs of B. burgdorferi have been definitively identified, and none are well characterized structurally. Here, we provide evidence that the borrelial OMP P66, a known adhesin with pore-forming activity, forms a β-barrel in the B. burgdorferi OM. Multiple computer-based algorithms predict that P66 forms a β-barrel with either 22 or 24 transmembrane domains. According to our predicted P66 topology, a lysine residue (K487) known to be sensitive to trypsin cleavage is located within a surface-exposed loop. When we aligned the mature P66 amino acid sequences from B. burgdorferi and B. garinii, we found that K487 was present only in the B. burgdorferi P66 protein sequence. When intact cells from each strain were treated with trypsin, only B. burgdorferi P66 was trypsin sensitive, indicating that K487 is surface exposed, as predicted. Consistent with this observation, when we inserted a c-Myc tag adjacent to K487 and utilized surface localization immunofluorescence, we detected the loop containing K487 on the surface of B. burgdorferi. P66 was examined by both Triton X-114 phase partitioning and circular dichroism, confirming that the protein is amphiphilic and contains extensive (48%) β-sheets, respectively. Moreover, P66 also was able to incorporate into liposomes and form channels in large unilamellar vesicles. Finally, blue native PAGE (BN-PAGE) revealed that under nondenaturing conditions, P66 is found in large complexes of ∼400 kDa and ∼600 kDa. Outer surface lipoprotein A (OspA) and OspB both coimmunoprecipitate with P66, demonstrating that P66 associates with OspA and OspB in B. burgdorferi. The combined computer-based structural analyses and supporting physicochemical properties of P66 provide a working model to further examine the porin and integrin-binding activities of this OMP as they relate to B. burgdorferi physiology and Lyme disease pathogenesis.
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20
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Bárcena-Uribarri I, Thein M, Maier E, Bonde M, Bergström S, Benz R. Use of nonelectrolytes reveals the channel size and oligomeric constitution of the Borrelia burgdorferi P66 porin. PLoS One 2013; 8:e78272. [PMID: 24223145 PMCID: PMC3819385 DOI: 10.1371/journal.pone.0078272] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 09/18/2013] [Indexed: 11/19/2022] Open
Abstract
In the Lyme disease spirochete Borrelia burgdorferi, the outer membrane protein P66 is capable of pore formation with an atypical high single-channel conductance of 11 nS in 1 M KCl, which suggested that it could have a larger diameter than 'normal' Gram-negative bacterial porins. We studied the diameter of the P66 channel by analyzing its single-channel conductance in black lipid bilayers in the presence of different nonelectrolytes with known hydrodynamic radii. We calculated the filling of the channel with these nonelectrolytes and the results suggested that nonelectrolytes (NEs) with hydrodynamic radii of 0.34 nm or smaller pass through the pore, whereas neutral molecules with greater radii only partially filled the channel or were not able to enter it at all. The diameter of the entrance of the P66 channel was determined to be ≤1.9 nm and the channel has a central constriction of about 0.8 nm. The size of the channel appeared to be symmetrical as judged from one-sidedness of addition of NEs. Furthermore, the P66-induced membrane conductance could be blocked by 80-90% by the addition of the nonelectrolytes PEG 400, PEG 600 and maltohexaose to the aqueous phase in the low millimolar range. The analysis of the power density spectra of ion current through P66 after blockage with these NEs revealed no chemical reaction responsible for channel block. Interestingly, the blockage of the single-channel conductance of P66 by these NEs occurred in about eight subconductance states, indicating that the P66 channel could be an oligomer of about eight individual channels. The organization of P66 as a possible octamer was confirmed by Blue Native PAGE and immunoblot analysis, which both demonstrated that P66 forms a complex with a mass of approximately 460 kDa. Two dimension SDS PAGE revealed that P66 is the only polypeptide in the complex.
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Affiliation(s)
- Iván Bárcena-Uribarri
- School of Engineering and Science, Jacobs University Bremen, Bremen, Germany
- Rudolf-Virchow-Center, DFG-Research Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Marcus Thein
- Rudolf-Virchow-Center, DFG-Research Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Elke Maier
- Rudolf-Virchow-Center, DFG-Research Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Mari Bonde
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Sven Bergström
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Roland Benz
- School of Engineering and Science, Jacobs University Bremen, Bremen, Germany
- Rudolf-Virchow-Center, DFG-Research Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
- * E-mail:
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21
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Ristow LC, Miller HE, Padmore LJ, Chettri R, Salzman N, Caimano MJ, Rosa PA, Coburn J. The β₃-integrin ligand of Borrelia burgdorferi is critical for infection of mice but not ticks. Mol Microbiol 2012; 85:1105-18. [PMID: 22758390 DOI: 10.1111/j.1365-2958.2012.08160.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
P66 is a Borrelia burgdorferi surface protein with β₃ integrin binding and channel forming activities. In this study, the role of P66 in mammalian and tick infection was examined. B. burgdorferiΔp66 strains were not infectious in wild-type, TLR2⁻/⁻- or MyD88⁻/⁻-deficient mice. Strains with p66 restored to the chromosome restored near wild-type infectivity, while complementation with p66 on a shuttle vector did not restore infectivity. Δp66 mutants are cleared quickly from the site of inoculation, but analyses of cytokine expression and cellular infiltrates at the site of inoculation did not reveal a specific mechanism of clearance. The defect in these mutants cannot be attributed to nutrient limitation or an inability to adapt to the host environment in vivo as Δp66 bacteria were able to survive as well as wild type in dialysis membrane chambers in the rat peritoneum. Δp66 bacteria were able to survive in ticks through the larva to nymph moult, but were non-infectious in mice when delivered by tick bite. Independent lines of evidence do not support any increased susceptibility of the Δp66 strains to factors in mammalian blood. This study is the first to define a B. burgdorferi adhesin as essential for mammalian, but not tick infection.
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Affiliation(s)
- Laura C Ristow
- Graduate Program in Microbiology, Immunology, and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI, USA
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22
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Kenedy MR, Lenhart TR, Akins DR. The role of Borrelia burgdorferi outer surface proteins. ACTA ACUST UNITED AC 2012; 66:1-19. [PMID: 22540535 DOI: 10.1111/j.1574-695x.2012.00980.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 04/13/2012] [Accepted: 04/25/2012] [Indexed: 12/18/2022]
Abstract
Human pathogenic spirochetes causing Lyme disease belong to the Borrelia burgdorferi sensu lato complex. Borrelia burgdorferi organisms are extracellular pathogens transmitted to humans through the bite of Ixodes spp. ticks. These spirochetes are unique in that they can cause chronic infection and persist in the infected human, even though a robust humoral and cellular immune response is produced by the infected host. How this extracellular pathogen is able to evade the host immune response for such long periods of time is currently unclear. To gain a better understanding of how this organism persists in the infected human, many laboratories have focused on identifying and characterizing outer surface proteins of B. burgdorferi. As the interface between B. burgdorferi and its human host is its outer surface, proteins localized to the outer membrane must play an important role in dissemination, virulence, tissue tropism, and immune evasion. Over the last two decades, numerous outer surface proteins from B. burgdorferi have been identified, and more recent studies have begun to elucidate the functional role(s) of many borrelial outer surface proteins. This review summarizes the outer surface proteins identified in B. burgdorferi to date and provides detailed insight into the functions of many of these proteins as they relate to the unique parasitic strategy of this spirochetal pathogen.
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Affiliation(s)
- Melisha R Kenedy
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, USA
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23
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Thein M, Bonde M, Bunikis I, Denker K, Sickmann A, Bergström S, Benz R. DipA, a pore-forming protein in the outer membrane of Lyme disease spirochetes exhibits specificity for the permeation of dicarboxylates. PLoS One 2012; 7:e36523. [PMID: 22590556 PMCID: PMC3349712 DOI: 10.1371/journal.pone.0036523] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 04/03/2012] [Indexed: 11/18/2022] Open
Abstract
Lyme disease Borreliae are highly dependent on the uptake of nutrients provided by their hosts. Our study describes the identification of a 36 kDa protein that functions as putative dicarboxylate-specific porin in the outer membrane of Lyme disease Borrelia. The protein was purified by hydroxyapatite chromatography from Borrelia burgdorferi B31 and designated as DipA, for dicarboxylate-specific porin A. DipA was partially sequenced, and corresponding genes were identified in the genomes of B. burgdorferi B31, Borrelia garinii PBi and Borrelia afzelii PKo. DipA exhibits high homology to the Oms38 porins of relapsing fever Borreliae. B. burgdorferi DipA was characterized using the black lipid bilayer assay. The protein has a single-channel conductance of 50 pS in 1 M KCl, is slightly selective for anions with a permeability ratio for cations over anions of 0.57 in KCl and is not voltage-dependent. The channel could be partly blocked by different di- and tricarboxylic anions. Particular high stability constants up to about 28,000 l/mol (in 0.1 M KCl) were obtained among the 11 tested anions for oxaloacetate, 2-oxoglutarate and citrate. The results imply that DipA forms a porin specific for dicarboxylates which may play an important role for the uptake of specific nutrients in different Borrelia species.
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Affiliation(s)
- Marcus Thein
- Rudolf-Virchow-Center, DFG-Research Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Mari Bonde
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Ignas Bunikis
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Katrin Denker
- Rudolf-Virchow-Center, DFG-Research Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Albert Sickmann
- Rudolf-Virchow-Center, DFG-Research Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
- Department of Bioanalytics, Leibniz-Institut für Analytische Wissenschaften – ISAS, Dortmund, Germany
| | - Sven Bergström
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Roland Benz
- Rudolf-Virchow-Center, DFG-Research Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
- School of Engineering and Science, Jacobs University Bremen, Bremen, Germany
- * E-mail:
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24
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Miklossy J. Alzheimer's disease - a neurospirochetosis. Analysis of the evidence following Koch's and Hill's criteria. J Neuroinflammation 2011; 8:90. [PMID: 21816039 PMCID: PMC3171359 DOI: 10.1186/1742-2094-8-90] [Citation(s) in RCA: 217] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 08/04/2011] [Indexed: 12/14/2022] Open
Abstract
It is established that chronic spirochetal infection can cause slowly progressive dementia, brain atrophy and amyloid deposition in late neurosyphilis. Recently it has been suggested that various types of spirochetes, in an analogous way to Treponema pallidum, could cause dementia and may be involved in the pathogenesis of Alzheimer's disease (AD). Here, we review all data available in the literature on the detection of spirochetes in AD and critically analyze the association and causal relationship between spirochetes and AD following established criteria of Koch and Hill. The results show a statistically significant association between spirochetes and AD (P = 1.5 × 10-17, OR = 20, 95% CI = 8-60, N = 247). When neutral techniques recognizing all types of spirochetes were used, or the highly prevalent periodontal pathogen Treponemas were analyzed, spirochetes were observed in the brain in more than 90% of AD cases. Borrelia burgdorferi was detected in the brain in 25.3% of AD cases analyzed and was 13 times more frequent in AD compared to controls. Periodontal pathogen Treponemas (T. pectinovorum, T. amylovorum, T. lecithinolyticum, T. maltophilum, T. medium, T. socranskii) and Borrelia burgdorferi were detected using species specific PCR and antibodies. Importantly, co-infection with several spirochetes occurs in AD. The pathological and biological hallmarks of AD were reproduced in vitro by exposure of mammalian cells to spirochetes. The analysis of reviewed data following Koch's and Hill's postulates shows a probable causal relationship between neurospirochetosis and AD. Persisting inflammation and amyloid deposition initiated and sustained by chronic spirochetal infection form together with the various hypotheses suggested to play a role in the pathogenesis of AD a comprehensive entity. As suggested by Hill, once the probability of a causal relationship is established prompt action is needed. Support and attention should be given to this field of AD research. Spirochetal infection occurs years or decades before the manifestation of dementia. As adequate antibiotic and anti-inflammatory therapies are available, as in syphilis, one might prevent and eradicate dementia.
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Affiliation(s)
- Judith Miklossy
- International Alzheimer Research Center, Prevention Alzheimer Foundation, Martigny-Combe, Switzerland.
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Abstract
The contributions of early British colonial and German scientists to the elucidation of the nature of spirochaetes, are contrasted. Recently, after a lapse of nearly three-quarters of a century, there has been a revival of interest by German microbiologists in investigating the borreliae.
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Affiliation(s)
- D J M Wright
- Microbiology, Charing Cross Hospital Plastic Surgery, Royal London Hospital, London, UK.
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Abstract
Gram-negative bacteria and mitochondria are both covered by two distinct biological membranes. These membrane systems have been maintained during the course of evolution from an early evolutionary precursor. Both outer membranes accommodate channels of the porin family, which are designed for the uptake and exchange of metabolites, including ions and small molecules, such as nucleosides or sugars. In bacteria, the structure of the outer membrane porin protein family of β-barrels is generally characterized by an even number of β-strands; usually 14, 16 or 18 strands are observed forming the bacterial porin barrel wall. In contrast, the recent structures of the mitochondrial porin, also known as VDAC (voltage-dependent anion channel), show an uneven number of 19 β-strands, but a similar molecular architecture. Despite the lack of a clear evolutionary link between these protein families, their common principles and differences in assembly, architecture and function are summarized in the present review.
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