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Thomas S, Schulz AM, Leong JM, Zeczycki TN, Garcia BL. The molecular determinants of classical pathway complement inhibition by OspEF-related proteins of Borrelia burgdorferi. J Biol Chem 2024; 300:107236. [PMID: 38552741 PMCID: PMC11066524 DOI: 10.1016/j.jbc.2024.107236] [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: 01/26/2024] [Revised: 03/18/2024] [Accepted: 03/22/2024] [Indexed: 04/04/2024] Open
Abstract
The complement system serves as the first line of defense against invading pathogens by promoting opsonophagocytosis and bacteriolysis. Antibody-dependent activation of complement occurs through the classical pathway and relies on the activity of initiating complement proteases of the C1 complex, C1r and C1s. The causative agent of Lyme disease, Borrelia burgdorferi, expresses two paralogous outer surface lipoproteins of the OspEF-related protein family, ElpB and ElpQ, that act as specific inhibitors of classical pathway activation. We have previously shown that ElpB and ElpQ bind directly to C1r and C1s with high affinity and specifically inhibit C2 and C4 cleavage by C1s. To further understand how these novel protease inhibitors function, we carried out a series of hydrogen-deuterium exchange mass spectrometry (HDX-MS) experiments using ElpQ and full-length activated C1s as a model of Elp-protease interaction. Comparison of HDX-MS profiles between unbound ElpQ and the ElpQ/C1s complex revealed a putative C1s-binding site on ElpQ. HDX-MS-guided, site-directed ElpQ mutants were generated and tested for direct binding to C1r and C1s using surface plasmon resonance. Several residues within the C-terminal region of ElpQ were identified as important for protease binding, including a single conserved tyrosine residue that was required for ElpQ- and ElpB-mediated complement inhibition. Collectively, our study identifies key molecular determinants for classical pathway protease recognition by Elp proteins. This investigation improves our understanding of the unique complement inhibitory mechanism employed by Elp proteins which serve as part of a sophisticated complement evasion system present in Lyme disease spirochetes.
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Affiliation(s)
- Sheila Thomas
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Anna M Schulz
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - John M Leong
- Department of Molecular Biology and Microbiology, Tufts School of Medicine, Tufts University, Boston, Massachusetts, USA
| | - Tonya N Zeczycki
- Department of Biochemistry & Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Brandon L Garcia
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA.
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2
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Cramer NA, Socarras KM, Earl J, Ehrlich GD, Marconi RT. Borreliella burgdorferi factor H-binding proteins are not required for serum resistance and infection in mammals. Infect Immun 2024; 92:e0052923. [PMID: 38289123 PMCID: PMC10929407 DOI: 10.1128/iai.00529-23] [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: 12/22/2023] [Accepted: 01/02/2024] [Indexed: 03/13/2024] Open
Abstract
The causative agent of Lyme disease (LD), Borreliella burgdorferi, binds factor H (FH) and other complement regulatory proteins to its surface. B. burgdorferi B31 (type strain) encodes five FH-binding proteins (FHBPs): CspZ, CspA, and the OspE paralogs OspEBBN38, OspEBBL39, and OspEBBP38. This study assessed potential correlations between the production of individual FHBPs, FH-binding ability, and serum resistance using a panel of infectious B. burgdorferi clonal populations recovered from dogs. FHBP production was assessed in cultivated spirochetes and by antibody responses in naturally infected humans, dogs, and eastern coyotes (wild canids). FH binding specificity and sensitivity to dog and human serum were also assessed and compared. No correlation was observed between the production of individual FHBPs and FH binding with serum resistance, and CspA was determined to not be produced in animals. Notably, one or more clones isolated from dogs lacked CspZ or the OspE proteins (a finding confirmed by genome sequence determination) and did not bind FH derived from canines. The data presented do not support a correlation between FH binding and the production of individual FHBPs with serum resistance and infectivity. In addition, the limited number and polymorphic nature of cp32s in B. burgdorferi clone DRI85A that were identified through genome sequencing suggest no strict requirement for a defined set of these replicons for infectivity. This study reveals that the immune evasion mechanisms employed by B. burgdorferi are diverse, complex, and yet to be fully defined.
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Affiliation(s)
- Nicholas A. Cramer
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, Virginia, USA
| | - Kalya M. Socarras
- Department of Microbiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Joshua Earl
- Department of Microbiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Garth D. Ehrlich
- Department of Microbiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Richard T. Marconi
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, Virginia, USA
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3
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Stevenson B, Brissette CA. Erp and Rev Adhesins of the Lyme Disease Spirochete's Ubiquitous cp32 Prophages Assist the Bacterium during Vertebrate Infection. Infect Immun 2023; 91:e0025022. [PMID: 36853019 PMCID: PMC10016077 DOI: 10.1128/iai.00250-22] [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] [Indexed: 03/01/2023] Open
Abstract
Almost all spirochetes in the genus Borrelia (sensu lato) naturally contain multiple variants of closely related prophages. In the Lyme disease borreliae, these prophages are maintained as circular episomes that are called circular plasmid 32 kb (cp32s). The cp32s of Lyme agents are particularly unique in that they encode two distinct families of lipoproteins, namely, Erp and Rev, that are expressed on the bacterial outer surface during infection of vertebrate hosts. All identified functions of those outer surface proteins involve interactions between the spirochetes and host molecules, as follows: Erp proteins bind plasmin(ogen), laminin, glycosaminoglycans, and/or components of complement and Rev proteins bind fibronectin. Thus, cp32 prophages provide their bacterial hosts with surface proteins that can enhance infection processes, thereby facilitating their own survival. Horizontal transfer via bacteriophage particles increases the spread of beneficial alleles and creates diversity among Erp and Rev proteins.
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Affiliation(s)
- Brian Stevenson
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky, USA
- Department of Entomology, University of Kentucky, Lexington, Kentucky, USA
| | - Catherine A. Brissette
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, North Dakota, USA
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4
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Outer surface protein E (OspE) mediates Borrelia burgdorferi sensu stricto strain-specific complement evasion in the eastern fence lizard, Sceloporus undulatus. Ticks Tick Borne Dis 2023; 14:102081. [PMID: 36403322 DOI: 10.1016/j.ttbdis.2022.102081] [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: 06/17/2022] [Revised: 10/31/2022] [Accepted: 11/01/2022] [Indexed: 11/11/2022]
Abstract
In North America, Lyme disease is primarily caused by the spirochetal bacterium Borrelia burgdorferi sensu stricto (Bb), which is transmitted between multiple vertebrate hosts and ixodid ticks, and is a model commonly used to study host-pathogen interactions. While Bb is consistently observed in its mammalian and avian reservoirs, the bacterium is rarely isolated from North American reptiles. Two closely related lizard species, the eastern fence lizard (Sceloporus undulatus) and the western fence lizard (Sceloporus occidentalis), are examples of reptiles parasitized by Ixodes ticks. Vertebrates are known to generate complement as an innate defense mechanism, which can be activated before Bb disseminate to distal tissues. Complement from western fence lizards has proven lethal against one Bb strain, implying the role of complement in making those lizards unable to serve as hosts to Bb. However, Bb DNA is occasionally identified in distal tissues of field-collected eastern fence lizards, suggesting some Bb strains may overcome complement-mediated clearance in these lizards. These findings raise questions regarding the role of complement and its impact on Bb interactions with North American lizards. In this study, we found Bb seropositivity in a small population of wild-caught eastern fence lizards and observed Bb strain-specific survivability in lizard sera. We also found that a Bb outer surface protein, OspE, from Bb strains viable in sera, promotes lizard serum survivability and binds to a complement inhibitor, factor H, from eastern fence lizards. Our data thus identify bacterial and host determinants of eastern fence lizard complement evasion, providing insights into the role of complement influencing Bb interactions with North American lizards.
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5
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Lin YP, Diuk-Wasser MA, Stevenson B, Kraiczy P. Complement Evasion Contributes to Lyme Borreliae-Host Associations. Trends Parasitol 2020; 36:634-645. [PMID: 32456964 DOI: 10.1016/j.pt.2020.04.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/17/2020] [Accepted: 04/17/2020] [Indexed: 01/31/2023]
Abstract
Lyme disease is the most common vector-borne disease in the northern hemisphere and is caused by spirochetes of the Borrelia burgdorferi sensu lato complex. Lyme borreliae infect diverse vertebrate reservoirs without triggering apparent manifestations in these animals; however, Lyme borreliae strains differ in their reservoir hosts. The mechanisms that drive those differences are unknown. To survive in vertebrate hosts, Lyme borreliae require the ability to escape from host defense mechanisms, in particular complement. To facilitate the evasion of complement, Lyme borreliae produce diverse proteins at different stages of infection, allowing them to persistently survive without being recognized by hosts and potentially resulting in host-specific infection. This review discusses the current knowledge regarding the ecology and evolutionary mechanisms of Lyme borreliae-host associations driven by complement evasion.
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Affiliation(s)
- Yi-Pin Lin
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, USA; Department of Biomedical Science, State University of New York at Albany, NY, USA.
| | - Maria A Diuk-Wasser
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY, USA
| | - Brian Stevenson
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY, USA; Department of Entomology, University of Kentucky, Lexington, KY, USA
| | - Peter Kraiczy
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Goethe University Frankfurt, D-60596 Frankfurt, Germany.
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6
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Lin YP, Frye AM, Nowak TA, Kraiczy P. New Insights Into CRASP-Mediated Complement Evasion in the Lyme Disease Enzootic Cycle. Front Cell Infect Microbiol 2020; 10:1. [PMID: 32083019 PMCID: PMC7002432 DOI: 10.3389/fcimb.2020.00001] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 01/06/2020] [Indexed: 12/23/2022] Open
Abstract
Lyme disease (LD), which is caused by genospecies of the Borrelia burgdorferi sensu lato complex, is the most common vector-borne disease in the Northern hemisphere. Spirochetes are transmitted by Ixodes ticks and maintained in diverse vertebrate animal hosts. Following tick bite, spirochetes initially establish a localized infection in the skin. However, they may also disseminate hematogenously to several distal sites, including heart, joints, or the CNS. Because they need to survive in diverse microenvironments, from tick vector to mammalian hosts, spirochetes have developed multiple strategies to combat the numerous host defense mechanisms. One of these strategies includes the production of a number of complement-regulator acquiring surface proteins (CRASPs) which encompass CspA, CspZ, and OspE paralogs to blunt the complement pathway. These proteins are capable of preventing complement activation on the spirochete surface by binding to complement regulator Factor H. The genes encoding these CRASPs differ in their expression patterns during the tick-to-host infection cycle, implying that these proteins may exhibit different functions during infection. This review summarizes the recent published reports which investigated the roles that each of these molecules plays in conferring tick-borne transmission and dissemination in vertebrate hosts. These findings offer novel mechanistic insights into LD pathobiology and may facilitate the identification of new targets for preventive strategies against Lyme borreliosis.
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Affiliation(s)
- Yi-Pin Lin
- Department of Biomedical Sciences, State University of New York at Albany, Albany, NY, United States
- Division of Infectious Diseases, New York State Department of Health, Wadsworth Center, Albany, NY, United States
| | - Amber M. Frye
- Department of Biomedical Sciences, State University of New York at Albany, Albany, NY, United States
- Division of Infectious Diseases, New York State Department of Health, Wadsworth Center, Albany, NY, United States
| | - Tristan A. Nowak
- Department of Biomedical Sciences, State University of New York at Albany, Albany, NY, United States
- Division of Infectious Diseases, New York State Department of Health, Wadsworth Center, Albany, NY, United States
| | - Peter Kraiczy
- Institute of Medical Microbiology and Infection Control, University Hospital, Goethe University Frankfurt, Frankfurt, Germany
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7
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Tufts DM, Hart TM, Chen GF, Kolokotronis SO, Diuk-Wasser MA, Lin YP. Outer surface protein polymorphisms linked to host-spirochete association in Lyme borreliae. Mol Microbiol 2019; 111:868-882. [PMID: 30666741 DOI: 10.1111/mmi.14209] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/16/2019] [Indexed: 12/15/2022]
Abstract
Lyme borreliosis is caused by multiple species of the spirochete bacteria Borrelia burgdorferi sensu lato. The spirochetes are transmitted by ticks to vertebrate hosts, including small- and medium-sized mammals, birds, reptiles, and humans. Strain-to-strain variation in host-specific infectivity has been documented, but the molecular basis that drives this differentiation is still unclear. Spirochetes possess the ability to evade host immune responses and colonize host tissues to establish infection in vertebrate hosts. In turn, hosts have developed distinct levels of immune responses when invaded by different species/strains of Lyme borreliae. Similarly, the ability of Lyme borreliae to colonize host tissues varies among different spirochete species/strains. One potential mechanism that drives this strain-to-strain variation of immune evasion and colonization is the polymorphic outer surface proteins produced by Lyme borreliae. In this review, we summarize research on strain-to-strain variation in host competence and discuss the evidence that supports the role of spirochete-produced protein polymorphisms in driving this variation in host specialization. Such information will provide greater insights into the adaptive mechanisms driving host and Lyme borreliae association, which will lead to the development of interventions to block pathogen spread and eventually reduce Lyme borreliosis health burden.
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Affiliation(s)
- Danielle M Tufts
- Department of Ecology, Evolution, and Environmental Biology, Columbia University, New York, NY, USA
| | - Thomas M Hart
- Department of Biological Sciences, University at Albany, Albany, NY, USA.,Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Grace F Chen
- Department of Biology, Misericordia University, Dallas, PA, USA
| | - Sergios-Orestis Kolokotronis
- Department of Epidemiology and Biostatistics, School of Public Health, SUNY Downstate Medical Center, Brooklyn, NY, USA
| | - Maria A Diuk-Wasser
- Department of Ecology, Evolution, and Environmental Biology, Columbia University, New York, NY, USA
| | - Yi-Pin Lin
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY, USA.,Department of Biomedical Sciences, University at Albany, Albany, NY, USA
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8
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Mühleip JJ, Lin YP, Kraiczy P. Further Insights Into the Interaction of Human and Animal Complement Regulator Factor H With Viable Lyme Disease Spirochetes. Front Vet Sci 2019; 5:346. [PMID: 30766876 PMCID: PMC6365980 DOI: 10.3389/fvets.2018.00346] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 12/28/2018] [Indexed: 12/19/2022] Open
Abstract
Spirochetes belonging to the Borrelia (B.) burgdorferi sensu lato (s.l.) complex differ in their ability to establish infection and to survive in diverse vertebrate hosts. Association with and adaption to various hosts most likely correlates with the spirochetes' ability to acquire complement regulator factor H (FH) to overcome the host's innate immune response. Here we assessed binding of serum FH from human and various animals including bovine, cat, chicken, dog, horse, mouse, rabbit, and rat to viable B. burgdorferi sensu stricto (s.s.), B. afzelii, B. garinii, B. spielmanii, B. valaisiana, and B. lusitaniae. Spirochetes ectopically producing CspA orthologs of B. burgdorferi s.s., B. afzelii, and B. spielmanii, CspZ, ErpC, and ErpP, respectively, were also investigated. Our comparative analysis using viable bacterial cells revealed a striking heterogeneity among Lyme disease spirochetes regarding their FH-binding patterns that almost mirrors the serum susceptibility of the respective borrelial genospecies. Moreover, native CspA from B. burgdorferi s.s., B. afzelii, and B. spielmanii as well as CspZ were identified as key ligands of FH from human, horse, and rat origin while ErpP appears to bind dog and mouse FH and to a lesser extent human FH. By contrast, ErpC did not bind FH from human as well as from animal origin. These findings indicate a strong restriction of distinct borrelial proteins toward binding of polymorphic FH of various vertebrate hosts.
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Affiliation(s)
- Jovana Jasmin Mühleip
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Frankfurt, Germany
| | - Yi-Pin Lin
- Department of Biomedical Science, State University of New York at Albany, Albany, NY, United States.,Division of Infectious Diseases, New York State Department of Health, Wadsworth Center, Albany, NY, United States
| | - Peter Kraiczy
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Frankfurt, Germany
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9
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Bencurova E, Gupta SK, Oskoueian E, Bhide M, Dandekar T. Omics and bioinformatics applied to vaccine development against Borrelia. Mol Omics 2018; 14:330-340. [PMID: 30113617 DOI: 10.1039/c8mo00130h] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Borrelia burgdorferi is an extracellular spirochete that causes Lyme disease. Currently, no effective vaccine is available for humans and animals except for dogs. In the present study, an extensive bioinformatics pipeline was established to predict new candidates that can be used for vaccine development including building the protein-protein interaction network based on orthologues of experimentally verified protein-protein interaction networks, elucidation of the proteins involved in the immune response, selection of the topologically-interesting proteins and their prioritization based on their antigenicity. Proteomic network analysis yielded an interactome network with 120 nodes with 97 interactions. Proteins were selected to obtain a subnet containing only the borrelial membrane proteins and immune-related host proteins. This strategy resulted in the selection of 15 borrelial targets, which were subjected to extensive bioinformatics analysis to predict their antigenic properties. Based on the strategy applied in this study the proteins encoded by erpX (ErpX proteins, UniProt ID: H7C7L6), erpL (ErpL protein, UniProt ID: H7C7M3) and erpY (ErpY protein, UniProt ID: Q9S0D9) are suggested as a novel set of vaccine targets to control Lyme disease. Moreover, five different tools were used to validate their antigenicity regarding B-cells. The combination of all these proteins in a vaccine should allow improved protection against Borrelia infection.
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Affiliation(s)
- Elena Bencurova
- Department of Bioinformatics, Biocenter, Am Hubland, D-97074 Wuerzburg, Germany.
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10
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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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11
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Borrelia burgdorferi surface protein Lmp1 facilitates pathogen dissemination through ticks as studied by an artificial membrane feeding system. Sci Rep 2018; 8:1910. [PMID: 29382879 PMCID: PMC5790009 DOI: 10.1038/s41598-018-20208-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 01/15/2018] [Indexed: 12/17/2022] Open
Abstract
In its natural infection cycle, the pathogen of Lyme borreliosis transits between a tick vector and a mammalian host. As relatively a minor fraction of spirochetes transits between the host and the vector precluding their reliable detection at early infection, artificial membrane feeders emerged as useful tools to study roles of spirochete proteins in pathogen entry, persistence, and exit through ticks. Here we report the development of a modified membrane feeder to study the role of a Borrelia burgdorferi surface protein called Lmp1 in spirochete transitions between the murine host and ticks. We show that our membrane feeder supports the blood meal engorgement process where ticks can acquire spirochetes from the feeder containing extremely low levels of pathogens (102 cells/ml of blood). Our data revealed that in comparison to wild-type spirochetes, lmp1 deletion mutants are significantly impaired for acquisition in naïve ticks as well as transmission from infected ticks. Taking together, our data suggest that Lmp1 plays an essential role in spirochete transitions between hosts and the vector. These studies also underscore the usefulness of artificial membrane feeding system as a valuable tool to study the role of B. burgdorferi gene-products in pathogen persistence in and passage through vector ticks.
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12
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Józsi M. Factor H Family Proteins in Complement Evasion of Microorganisms. Front Immunol 2017; 8:571. [PMID: 28572805 PMCID: PMC5435753 DOI: 10.3389/fimmu.2017.00571] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 04/28/2017] [Indexed: 01/08/2023] Open
Abstract
Human-pathogenic microbes possess various means to avoid destruction by our immune system. These include interactions with the host complement system that may facilitate pathogen entry into cells and tissues, expression of molecules that defuse the effector complement components and complexes, and acquisition of host complement inhibitors to downregulate complement activity on the surface of the pathogen. A growing number of pathogenic microorganisms have acquired the ability to bind the complement inhibitor factor H (FH) from body fluids and thus hijack its host protecting function. In addition to FH, binding of FH-related (FHR) proteins was also demonstrated for several microbes. Initial studies assumed that these proteins are complement inhibitors similar to FH. However, recent evidence suggests that FHR proteins may rather enhance complement activation both directly and also by competing with the inhibitor FH for binding to certain ligands and surfaces. This mini review focuses on the role of the main alternative pathway regulator FH in host–pathogen interactions, as well as on the emerging role of the FHR proteins as enhancers of complement activation.
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Affiliation(s)
- Mihály Józsi
- MTA-ELTE "Lendület" Complement Research Group, Department of Immunology, Eötvös Loránd University, Budapest, Hungary
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13
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Röttgerding F, Wagemakers A, Koetsveld J, Fingerle V, Kirschfink M, Hovius JW, Zipfel PF, Wallich R, Kraiczy P. Immune evasion of Borrelia miyamotoi: CbiA, a novel outer surface protein exhibiting complement binding and inactivating properties. Sci Rep 2017; 7:303. [PMID: 28331202 PMCID: PMC5428533 DOI: 10.1038/s41598-017-00412-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 02/27/2017] [Indexed: 12/13/2022] Open
Abstract
Borrelia (B.) miyamotoi, an emerging tick-borne relapsing fever spirochete, resists complement-mediated killing. To decipher the molecular principles of immune evasion, we sought to identify determinants contributing to complement resistance. Employing bioinformatics, we identified a gene encoding for a putative Factor H-binding protein, termed CbiA (complement binding and inhibitory protein A). Functional analyses revealed that CbiA interacted with complement regulator Factor H (FH), C3, C3b, C4b, C5, and C9. Upon binding to CbiA, FH retained its cofactor activity for Factor I-mediated inactivation of C3b. The Factor H-binding site within CbiA was mapped to domain 20 whereby the C-terminus of CbiA was involved in FH binding. Additionally, CbiA directly inhibited the activation of the classical pathway and the assembly of the terminal complement complex. Of importance, CbiA displayed inhibitory activity when ectopically produced in serum-sensitive B. garinii G1, rendering this surrogate strain resistant to human serum. In addition, long-term in vitro cultivation lead to an incremental loss of the cbiA gene accompanied by an increase in serum susceptibility. In conclusion, our data revealed a dual strategy of B. miyamotoi to efficiently evade complement via CbiA, which possesses complement binding and inhibitory activities.
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Affiliation(s)
- Florian Röttgerding
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Frankfurt, Germany
| | - Alex Wagemakers
- Center for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Joris Koetsveld
- Center for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Volker Fingerle
- National Reference Center for Borrelia, Oberschleißheim, Germany
| | | | - Joppe W Hovius
- Center for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Peter F Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany.,Friedrich Schiller University, Jena, Germany
| | - Reinhard Wallich
- Institute of Immunology, University of Heidelberg, Heidelberg, Germany
| | - Peter Kraiczy
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Frankfurt, Germany.
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14
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Marcinkiewicz AL, Kraiczy P, Lin YP. There Is a Method to the Madness: Strategies to Study Host Complement Evasion by Lyme Disease and Relapsing Fever Spirochetes. Front Microbiol 2017; 8:328. [PMID: 28303129 PMCID: PMC5332432 DOI: 10.3389/fmicb.2017.00328] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 02/16/2017] [Indexed: 01/04/2023] Open
Abstract
Lyme disease and relapsing fever are caused by various Borrelia species. Lyme disease borreliae, the most common vector-borne pathogens in both the U.S. and Europe, are transmitted by Ixodes ticks and disseminate from the site of tick bites to tissues leading to erythema migrans skin rash, arthritis, carditis, and neuroborreliosis. Relapsing fever borreliae, carried by ticks and lice, trigger reoccurring fever episodes. Following transmission, spirochetes survive in the blood to induce bacteremia at the early stages of infection, which is thought to promote evasion of the host complement system. The complement system acts as an important innate immune defense mechanism in humans and vertebrates. Upon activation, the cleaved complement components form complexes on the pathogen surface to eventually promote bacteriolysis. The complement system is negatively modulated by a number of functionally diverse regulators to avoid tissue damage. To evade and inhibit the complement system, spirochetes are capable of binding complement components and regulators. Complement inhibition results in bacterial survival in serum (serum resistance) and is thought to promote bloodstream survival, which facilitates spirochete dissemination and disease manifestations. In this review, we discuss current methodologies to elucidate the mechanisms of Borrelia spp. that promote serum resistance and bloodstream survival, as well as novel methods to study factors responsible for bloodstream survival of Lyme disease borreliae that can be applied to relapsing fever borreliae. Understanding the mechanisms these pathogens utilize to evade the complement system will ultimately aid in the development of novel therapeutic strategies and disease prevention to improve human health.
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Affiliation(s)
- Ashley L Marcinkiewicz
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health Albany, NY, USA
| | - Peter Kraiczy
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt am Main Frankfurt am Main, Germany
| | - Yi-Pin Lin
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health Albany, NY, USA
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15
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Abstract
The complement system plays an important role in the innate and acquired immune response against pathogens. A sophisticated network of activating and regulating proteins allows the distinction between intact and damaged host and non-host surfaces such as bacteria and other parasites. Non-host structures trigger the alternative pathway which may lead to their elimination by phagocytosis or cell lysis. In addition, complement proteins such as C1q, mannose binding lectin (MBL), and ficolins act as pathogen pattern-recognition molecules. Biological functions such as opsonization, activation of B lymphocytes and production of antibodies, degranulation of mast cells and basophils, and cell lysis that are important for elimination of microorganisms are dependent on complement activation. However, several pathogens including spirochetes have developed several specialized mechanisms to evade the complement system, thereby contributing to survival in the host. In this review, we give a brief overview of complement activation and regulation, and discuss in detail the strategies used by spirochetes from the genera Borrelia, Leptospira, and Treponema to overcome complement activation.
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16
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Eggers CH, Gray CM, Preisig AM, Glenn DM, Pereira J, Ayers RW, Alshahrani M, Acabbo C, Becker MR, Bruenn KN, Cheung T, Jendras TM, Shepley AB, Moeller JT. Phage-mediated horizontal gene transfer of both prophage and heterologous DNA by ϕBB-1, a bacteriophage of Borrelia burgdorferi. Pathog Dis 2016; 74:ftw107. [PMID: 27811049 DOI: 10.1093/femspd/ftw107] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 07/25/2016] [Accepted: 10/28/2016] [Indexed: 11/13/2022] Open
Abstract
Horizontal gene transfer (HGT) in Borrelia burgdorferi, the Lyme disease agent, is likely mediated by bacteriophage. Studies of the B. burgdorferi phage, ϕBB-1 and its role in HGT have been hindered by the lack of an assay for readily characterizing phage-mediated DNA movement (transduction). Here we describe an in vitro assay in which a clone of B. burgdorferi strain CA-11.2A encoding kanamycin resistance on a ϕBB-1 prophage is co-cultured with different clones encoding gentamicin resistance on a shuttle vector; transduction is monitored by enumerating colonies selected in the presence of both kanamycin and gentamicin. When both clones used in the assay were derived from CA-11.2A, the frequency of transduction was 1.23 × 10-6 transductants per cell, and could be increased 5-fold by exposing the phage-producing strain to 5% ethanol. Transduction was also demonstrated between the CA-11.2A clone and clones of both high-passage B. burgdorferi strain B31 and low-passage, virulent B. burgdorferi strain 297, although with lower transduction frequencies. The transductant in the 297 background produced phage capable of transducing another B. burgdorferi clone: this is the first experimental demonstration of transduction from a clone of a virulent strain. In addition to prophage DNA, small Escherichia coli-derived shuttle vectors were also transduced between co-cultured B. burgdorferi strains, suggesting both a broad role for the phage in the HGT of heterologous DNA and a potential use of the phage as a molecular tool. These results enhance our understanding of phage-mediated transduction as a mechanism of HGT in the Lyme disease spirochetes. Furthermore, the reagents and techniques developed herein will facilitate future studies of phage-mediated HGT, especially within the tick vector and vertebrate host.
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Affiliation(s)
- Christian H Eggers
- Department of Biomedical Sciences, Quinnipiac University, Hamden, CT 06518, USA
| | - Carlie M Gray
- Department of Biomedical Sciences, Quinnipiac University, Hamden, CT 06518, USA
| | - Alexander M Preisig
- Department of Biomedical Sciences, Quinnipiac University, Hamden, CT 06518, USA
| | - Danielle M Glenn
- Department of Biomedical Sciences, Quinnipiac University, Hamden, CT 06518, USA
| | - Jessica Pereira
- Department of Biomedical Sciences, Quinnipiac University, Hamden, CT 06518, USA
| | - Ryan W Ayers
- Department of Biomedical Sciences, Quinnipiac University, Hamden, CT 06518, USA
| | - Mohammad Alshahrani
- Department of Biomedical Sciences, Quinnipiac University, Hamden, CT 06518, USA
| | - Christopher Acabbo
- Department of Biomedical Sciences, Quinnipiac University, Hamden, CT 06518, USA
| | - Maria R Becker
- Department of Biomedical Sciences, Quinnipiac University, Hamden, CT 06518, USA
| | - Kimberly N Bruenn
- Department of Biomedical Sciences, Quinnipiac University, Hamden, CT 06518, USA
| | - Timothy Cheung
- Department of Biomedical Sciences, Quinnipiac University, Hamden, CT 06518, USA
| | - Taylor M Jendras
- Department of Biomedical Sciences, Quinnipiac University, Hamden, CT 06518, USA
| | - Aron B Shepley
- Department of Biomedical Sciences, Quinnipiac University, Hamden, CT 06518, USA
| | - John T Moeller
- Department of Biomedical Sciences, Quinnipiac University, Hamden, CT 06518, USA
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17
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Kraiczy P. Hide and Seek: How Lyme Disease Spirochetes Overcome Complement Attack. Front Immunol 2016; 7:385. [PMID: 27725820 PMCID: PMC5036304 DOI: 10.3389/fimmu.2016.00385] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 09/13/2016] [Indexed: 11/15/2022] Open
Abstract
Overcoming the first line of the innate immune system is a general hallmark of pathogenic microbes to avoid recognition and to enter the human host. In particular, spirochetes belonging to the Borrelia burgdorferi sensu lato complex have developed various means to counter the immune response and to successfully survive in diverse host environments for a prolonged period of time. In regard to complement resistance, Borrelia utilize a plethora of immune evasion strategies involves capturing of host-derived complement regulators, terminating complement activation as well as shedding of cell-destroying complement complexes to manipulate and to expeditiously inhibit human complement. Owing to their mode of action, the interacting surface-exposed proteins identified among B. burgdorferi sensu stricto (s.s.), Borrelia afzelii, Borrelia spielmanii, and Borrelia bavariensis can be classified into at least two major categories, namely, molecules that directly interfere with distinct complement components including BBK32, CspA, BGA66, BGA71, and a CD59-like protein or molecules, which indirectly counteract complement activation by binding various complement regulators such as Factor H, Factor H-like protein 1 (FHL-1), Factor H-related proteins FHR-1, FHR-2, or C4Bp. The latter group of genetically and structurally unrelated proteins has been collectively referred to as “complement regulator-acquiring surface proteins” and consists of CspA, CspZ, ErpA, ErpC, ErpP, and the as yet unidentified protein p43. This review focuses on the current knowledge of immune evasion mechanisms exhibited by Lyme disease spirochetes and highlights the role of complement-interfering, infection-associated molecules playing an important part in these processes. Deciphering the immune evasion strategies may provide novel avenues for improved diagnostic approaches and therapeutic interventions.
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Affiliation(s)
- Peter Kraiczy
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt , Frankfurt am Main , Germany
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18
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Granoff DM, Giuntini S, Gowans FA, Lujan E, Sharkey K, Beernink PT. Enhanced protective antibody to a mutant meningococcal factor H-binding protein with low-factor H binding. JCI Insight 2016; 1:e88907. [PMID: 27668287 DOI: 10.1172/jci.insight.88907] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Meningococcal factor H-binding protein (FHbp) is an antigen in 2 serogroup B meningococcal vaccines. FHbp specifically binds human and some nonhuman primate complement FH. To investigate the effect of binding of FH to FHbp on protective antibody responses, we immunized infant rhesus macaques with either a control recombinant FHbp antigen that bound macaque FH or a mutant antigen with 2 amino acid substitutions and >250-fold lower affinity for FH. The mutant antigen elicited 3-fold higher serum IgG anti-FHbp titers and up to 15-fold higher serum bactericidal titers than the control FHbp vaccine. When comparing sera with similar IgG anti-FHbp titers, the antibodies elicited by the mutant antigen gave greater deposition of complement component C4b on live meningococci (classical complement pathway) and inhibited binding of FH, while the anti-FHbp antibodies elicited by the control vaccine enhanced FH binding. Thus, the mutant FHbp vaccine elicited an anti-FHbp antibody repertoire directed at FHbp epitopes within the FH binding site, which resulted in greater protective activity than the antibodies elicited by the control vaccine, which targeted FHbp epitopes outside of the FH combining site. Binding of a host protein to a vaccine antigen impairs protective antibody responses, which can be overcome with low-binding mutant antigens.
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19
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The Treponema denticola FhbB Protein Is a Dominant Early Antigen That Elicits FhbB Variant-Specific Antibodies That Block Factor H Binding and Cleavage by Dentilisin. Infect Immun 2016; 84:2051-2058. [PMID: 27113359 DOI: 10.1128/iai.01542-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 04/19/2016] [Indexed: 12/19/2022] Open
Abstract
The Treponema denticola FhbB protein contributes to immune evasion by binding factor H (FH). Cleavage of FH by the T. denticola protease, dentilisin, may contribute to the local immune dysregulation that is characteristic of periodontal disease (PD). Although three FhbB phyletic types have been defined (FhbB1, FhbB2, and FhbB3), the in vivo expression patterns and antigenic heterogeneity of FhbB have not been assessed. Here, we demonstrate that FhbB is a dominant early antigen that elicits FhbB type-specific antibody (Ab) responses. Using the murine skin abscess model, we demonstrate that the presence or absence of FhbB or dentilisin significantly influences Ab responses to infection and skin abscess formation. Competitive binding analyses revealed that α-FhbB Ab can compete with FH for binding to T. denticola and block dentilisin-mediated FH cleavage. Lastly, we demonstrate that dentilisin cleavage sites reside within critical functional domains of FH, including the complement regulatory domain formed by CCPs 1 to 4. Analysis of the FH cleavage products revealed that they lack cofactor activity. The data presented here provide insight into the in vivo significance of dentilisin, FhbB and its antigenic diversity, and the potential impact of FH cleavage on the regulation of complement activation.
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20
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Travelling between Two Worlds: Complement as a Gatekeeper for an Expanded Host Range of Lyme Disease Spirochetes. Vet Sci 2016; 3:vetsci3020012. [PMID: 29056721 PMCID: PMC5644625 DOI: 10.3390/vetsci3020012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 06/03/2016] [Accepted: 06/06/2016] [Indexed: 01/21/2023] Open
Abstract
Evading innate immunity is a prerequisite for pathogenic microorganisms in order to survive in their respective hosts. Concerning Lyme disease spirochetes belonging to the Borrelia (B.) burgdorferi sensu lato group, a broad range of diverse vertebrates serve as reservoir or even as incidental hosts, including humans. The capability to infect multiple hosts implies that spirochetes have developed sophisticated means to counter the destructive effects of complement of humans and various animals. While the means by which spirochetes overcome the hosts immune defense are far from being completely understood, there is a growing body of evidence suggesting that binding of the key regulator of the alternative pathway, Factor H, plays a pivotal role for immune evasion and that Factor H is an important determinant of host specificity. This review covers (i) the contribution of complement in host-specificity and transmissibility of Lyme disease spirochetes; (ii) the involvement of borrelial-derived determinants to host specificity; (iii) the interplay of human and animal Factor H with complement-acquiring surface proteins of diverse borrelial species; and (iv) the potential role of additional animal complement proteins in the immune evasion of spirochetes.
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21
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The relapsing fever spirochete Borrelia miyamotoi resists complement-mediated killing by human serum. Ticks Tick Borne Dis 2014; 5:898-901. [DOI: 10.1016/j.ttbdis.2014.07.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 07/10/2014] [Indexed: 11/22/2022]
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22
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Groshong AM, Blevins JS. Insights into the biology of Borrelia burgdorferi gained through the application of molecular genetics. ADVANCES IN APPLIED MICROBIOLOGY 2014; 86:41-143. [PMID: 24377854 DOI: 10.1016/b978-0-12-800262-9.00002-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Borrelia burgdorferi, the vector-borne bacterium that causes Lyme disease, was first identified in 1982. It is known that much of the pathology associated with Lyme borreliosis is due to the spirochete's ability to infect, colonize, disseminate, and survive within the vertebrate host. Early studies aimed at defining the biological contributions of individual genes during infection and transmission were hindered by the lack of adequate tools and techniques for molecular genetic analysis of the spirochete. The development of genetic manipulation techniques, paired with elucidation and annotation of the B. burgdorferi genome sequence, has led to major advancements in our understanding of the virulence factors and the molecular events associated with Lyme disease. Since the dawn of this genetic era of Lyme research, genes required for vector or host adaptation have garnered significant attention and highlighted the central role that these components play in the enzootic cycle of this pathogen. This chapter covers the progress made in the Borrelia field since the application of mutagenesis techniques and how they have allowed researchers to begin ascribing roles to individual genes. Understanding the complex process of adaptation and survival as the spirochete cycles between the tick vector and vertebrate host will lead to the development of more effective diagnostic tools as well as identification of novel therapeutic and vaccine targets. In this chapter, the Borrelia genes are presented in the context of their general biological roles in global gene regulation, motility, cell processes, immune evasion, and colonization/dissemination.
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Affiliation(s)
- Ashley M Groshong
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Jon S Blevins
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
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23
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Hodzic E, Feng S, Barthold SW. Assessment of transcriptional activity of Borrelia burgdorferi and host cytokine genes during early and late infection in a mouse model. Vector Borne Zoonotic Dis 2013; 13:694-711. [PMID: 23930938 DOI: 10.1089/vbz.2012.1189] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Differential gene expression by Borrelia burgdorferi spirochetes during mammalian infection facilitates their dissemination as well as immune evasion. Modulation of gene transcription in response to host immunity has been documented with the outer surface protein C, but the influence of transcription of other genes is largely unknown. A low-density array (LDA) was developed to study transcriptional activity of 43 B. burgdorferi genes and 19 host genes that may be involved in various host-agent interactions. Gene transcription in heart, joint, and muscle tissue was compared in immunocompetent C3H and immunodeficient C3H-scid mice during early (3 weeks) and late (2 months) B. burgdorferi infection. Among all tissue types, levels of relative transcription of over 80% of B. burgdorferi genes tested were one- to nine-fold less in C3H mice compared to C3H-scid mice. At the later time point, all genes were transcribed in C3H-scid mice, whereas transcription of 16 genes out of 43 tested was not detected in analyzed tissues of C3H mice. Our data suggest that during infection of immunocompetent mice, a majority of B. burgdorferi genes tested are downregulated in response to acquired host immunity. LDA revealed variable patterns of host gene expression in different tissues and at different intervals in infected mice. Higher levels of relative expression for IL-10 during both early and late infection were detected in heart base, and it was unchanged in the tibiotarsal joint. Comparative analysis of B. burgdorferi and host genes transcriptional activity revealed that increased flaB mRNA during early infection was followed by increases of CCL7, CCL8, interleukin-10 (IL-10), and tumor necrosis factor-α (TNF-α) in all assessed tissue types. LDA represents a valuable approach for sensitive and quantitative gene transcription profiling and for understanding Lyme borreliosis.
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Affiliation(s)
- Emir Hodzic
- 1 Center for Comparative Medicine, Schools of Veterinary Medicine and Medicine, University of California at Davis , Davis, California
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24
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Jutras BL, Chenail AM, Carroll DW, Miller MC, Zhu H, Bowman A, Stevenson B. Bpur, the Lyme disease spirochete's PUR domain protein: identification as a transcriptional modulator and characterization of nucleic acid interactions. J Biol Chem 2013; 288:26220-26234. [PMID: 23846702 PMCID: PMC3764826 DOI: 10.1074/jbc.m113.491357] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The PUR domain is a nucleic acid-binding motif found in critical regulatory proteins of higher eukaryotes and in certain species of bacteria. During investigations into mechanisms by which the Lyme disease spirochete controls synthesis of its Erp surface proteins, it was discovered that the borrelial PUR domain protein, Bpur, binds with high affinity to double-stranded DNA adjacent to the erp transcriptional promoter. Bpur was found to enhance the effects of the erp repressor protein, BpaB. Bpur also bound single-stranded DNA and RNA, with relative affinities RNA > double-stranded DNA > single-stranded DNA. Rational site-directed mutagenesis of Bpur identified amino acid residues and domains critical for interactions with nucleic acids, and it revealed that the PUR domain has a distinct mechanism of interaction with each type of nucleic acid ligand. These data shed light on both gene regulation in the Lyme spirochete and functional mechanisms of the widely distributed PUR domain.
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Affiliation(s)
- Brandon L Jutras
- From the Department of Microbiology, Immunology, and Molecular Genetics and
| | - Alicia M Chenail
- From the Department of Microbiology, Immunology, and Molecular Genetics and
| | - Dustin W Carroll
- the Graduate Center for Toxicology, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - M Clarke Miller
- the James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky 40202, and
| | - Haining Zhu
- the Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - Amy Bowman
- From the Department of Microbiology, Immunology, and Molecular Genetics and
| | - Brian Stevenson
- From the Department of Microbiology, Immunology, and Molecular Genetics and.
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25
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Brisson D, Zhou W, Jutras BL, Casjens S, Stevenson B. Distribution of cp32 prophages among Lyme disease-causing spirochetes and natural diversity of their lipoprotein-encoding erp loci. Appl Environ Microbiol 2013; 79:4115-28. [PMID: 23624478 PMCID: PMC3697573 DOI: 10.1128/aem.00817-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 04/25/2013] [Indexed: 12/19/2022] Open
Abstract
Lyme disease spirochetes possess complex genomes, consisting of a main chromosome and 20 or more smaller replicons. Among those small DNAs are the cp32 elements, a family of prophages that replicate as circular episomes. All complete cp32s contain an erp locus, which encodes surface-exposed proteins. Sequences were compared for all 193 erp alleles carried by 22 different strains of Lyme disease-causing spirochete to investigate their natural diversity and evolutionary histories. These included multiple isolates from a focus where Lyme disease is endemic in the northeastern United States and isolates from across North America and Europe. Bacteria were derived from diseased humans and from vector ticks and included members of 5 different Borrelia genospecies. All erp operon 5'-noncoding regions were found to be highly conserved, as were the initial 70 to 80 bp of all erp open reading frames, traits indicative of a common evolutionary origin. However, the majority of the protein-coding regions are highly diverse, due to numerous intra- and intergenic recombination events. Most erp alleles are chimeras derived from sequences of closely related and distantly related erp sequences and from unknown origins. Since known functions of Erp surface proteins involve interactions with various host tissue components, this diversity may reflect both their multiple functions and the abilities of Lyme disease-causing spirochetes to successfully infect a wide variety of vertebrate host species.
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Affiliation(s)
- Dustin Brisson
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Wei Zhou
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Brandon L. Jutras
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Sherwood Casjens
- Department of Pathology, Division of Microbiology and Immunology, University of Utah Medical School, Salt Lake City, Utah, USA
| | - Brian Stevenson
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky, USA
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26
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Schwab J, Hammerschmidt C, Richter D, Skerka C, Matuschka FR, Wallich R, Zipfel PF, Kraiczy P. Borrelia valaisiana resist complement-mediated killing independently of the recruitment of immune regulators and inactivation of complement components. PLoS One 2013; 8:e53659. [PMID: 23320099 PMCID: PMC3539980 DOI: 10.1371/journal.pone.0053659] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 12/04/2012] [Indexed: 11/30/2022] Open
Abstract
Spirochetes belonging to the Borrelia (B.) burgdorferi sensu lato complex differ in their resistance to complement-mediated killing, particularly in regard to human serum. In the present study, we elucidate the serum and complement susceptibility of B. valaisiana, a genospecies with the potential to cause Lyme disease in Europe as well as in Asia. Among the investigated isolates, growth of ZWU3 Ny3 was not affected while growth of VS116 and Bv9 was strongly inhibited in the presence of 50% human serum. Analyzing complement activation, complement components C3, C4 and C6 were deposited on the surface of isolates VS116 and Bv9, and similarly the membrane attack complex was formed on their surface. In contrast, no surface-deposited components and no aberrations in cell morphology were detected for serum-resistant ZWU3 Ny3. While further investigating the protective role of bound complement regulators in mediating complement resistance, we discovered that none of the B. valaisiana isolates analyzed bound complement regulators Factor H, Factor H-like protein 1, C4b binding protein or C1 esterase inhibitor. In addition, B. valaisiana also lacked intrinsic proteolytic activity to degrade complement components C3, C3b, C4, C4b, and C5. Taken together, these findings suggest that certain B. valaisiana isolates differ in their capability to resist complement-mediating killing by human serum. The molecular mechanism utilized by B. valaisiana to inhibit bacteriolysis appears not to involve binding of the key host complement regulators of the alternative, classical, and lectin pathways as already known for serum-resistant Lyme disease or relapsing fever borreliae.
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Affiliation(s)
- Jasmin Schwab
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Frankfurt, Germany
| | - Claudia Hammerschmidt
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Frankfurt, Germany
| | - Dania Richter
- Abteilung Parasitologie, Institut für Pathologie, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Franz-Rainer Matuschka
- Abteilung Parasitologie, Institut für Pathologie, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Reinhard Wallich
- Institute of Immunology, University of Heidelberg, Heidelberg, Germany
| | - Peter F. Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
- Friedrich Schiller University, Jena, Germany
| | - Peter Kraiczy
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Frankfurt, Germany
- * E-mail:
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Changes in bacterial growth rate govern expression of the Borrelia burgdorferi OspC and Erp infection-associated surface proteins. J Bacteriol 2012; 195:757-64. [PMID: 23222718 DOI: 10.1128/jb.01956-12] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The Lyme disease spirochete controls production of its OspC and Erp outer surface proteins, repressing protein synthesis during colonization of vector ticks but increasing expression when those ticks feed on vertebrate hosts. Early studies found that the synthesis of OspC and Erps can be stimulated in culture by shifting the temperature from 23°C to 34°C, leading to a hypothesis that Borrelia burgdorferi senses environmental temperature to determine its location in the tick-mammal infectious cycle. However, borreliae cultured at 34°C divide several times faster than do those cultured at 23°C. We developed methods that disassociate bacterial growth rate and temperature, allowing a separate evaluation of each factor's impacts on B. burgdorferi gene and protein expression. Altogether, the data support a new paradigm that B. burgdorferi actually responds to changes in its own replication rate, not temperature per se, as the impetus to increase the expression of the OspC and Erp infection-associated proteins.
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Kraiczy P, Stevenson B. Complement regulator-acquiring surface proteins of Borrelia burgdorferi: Structure, function and regulation of gene expression. Ticks Tick Borne Dis 2012; 4:26-34. [PMID: 23219363 DOI: 10.1016/j.ttbdis.2012.10.039] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 10/15/2012] [Accepted: 10/16/2012] [Indexed: 12/27/2022]
Abstract
Borrelia burgdorferi, the etiological agent of Lyme disease, exploits an array of strategies to establish infection and to overcome host innate and adaptive immune responses. One key borrelial immune escape mechanism involves the inactivation of host complement attack through acquisition of human immune regulators factor H (CFH), factor H-like protein 1 (FHL1), factor H-related protein 1 (CFHR1), CFHR2, and/or CFHR5. Binding of these host proteins is primarily mediated by bacterial surface-exposed proteins that have been collectively referred to as complement regulator-acquiring surface proteins, or CRASPs. Different strains of B. burgdorferi produce as many as 5 different CRASP molecules that comprise 3 distinct, genetically unrelated groups. Depending on bacterial genetic composition, different combinations of these proteins can be found on the borrelial outer surface. The 3 groups differ in their gene location, gene regulatory mechanisms, expression patterns during the tick-mammal infection cycle, protein sequence and structure as well as binding affinity for complement regulators and other serum proteins. These attributes influence the proteins' abilities to contribute to complement resistance of this emerging human pathogen. In this review, we focus on the current knowledge on structure, function, and gene regulation of these B. burgdorferi infection-associated proteins.
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Affiliation(s)
- Peter Kraiczy
- Institute of Medical Microbiology and Infection Control, Frankfurt University Hospital, Paul-Ehrlich-Strasse 40, 6 Frankfurt, Germany.
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29
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Abstract
The spirochetes in the Borrelia burgdorferi sensu lato genospecies group cycle in nature between tick vectors and vertebrate hosts. The current assemblage of B. burgdorferi sensu lato, of which three species cause Lyme disease in humans, originated from a rapid species radiation that occurred near the origin of the clade. All of these species share a unique genome structure that is highly segmented and predominantly composed of linear replicons. One of the circular plasmids is a prophage that exists as several isoforms in each cell and can be transduced to other cells, likely contributing to an otherwise relatively anemic level of horizontal gene transfer, which nevertheless appears to be adequate to permit strong natural selection and adaptation in populations of B. burgdorferi. Although the molecular genetic toolbox is meager, several antibiotic-resistant mutants have been isolated, and the resistance alleles, as well as some exogenous genes, have been fashioned into markers to dissect gene function. Genetic studies have probed the role of the outer membrane lipoprotein OspC, which is maintained in nature by multiple niche polymorphisms and negative frequency-dependent selection. One of the most intriguing genetic systems in B. burgdorferi is vls recombination, which generates antigenic variation during infection of mammalian hosts.
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MESH Headings
- Alleles
- Animals
- Antigenic Variation
- Antigens, Bacterial/genetics
- Antigens, Bacterial/immunology
- Antigens, Bacterial/metabolism
- Bacterial Outer Membrane Proteins/genetics
- Bacterial Outer Membrane Proteins/metabolism
- Bacterial Proteins/genetics
- Bacterial Proteins/immunology
- Bacterial Proteins/metabolism
- Bacteriophages/genetics
- Bacteriophages/metabolism
- Bacteriophages/pathogenicity
- Borrelia burgdorferi/genetics
- Borrelia burgdorferi/immunology
- Borrelia burgdorferi/pathogenicity
- Borrelia burgdorferi/virology
- DNA, Bacterial/genetics
- DNA, Bacterial/metabolism
- Electroporation
- Evolution, Molecular
- Genes, Bacterial
- Genetic Variation
- Humans
- Ixodes/microbiology
- Linkage Disequilibrium
- Lipoproteins/genetics
- Lipoproteins/immunology
- Lipoproteins/metabolism
- Lyme Disease/microbiology
- Plasmids/genetics
- Plasmids/metabolism
- Prophages/genetics
- Prophages/metabolism
- Recombination, Genetic
- Selection, Genetic
- Species Specificity
- Transduction, Genetic
- Transformation, Genetic
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Affiliation(s)
- Dustin Brisson
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Dan Drecktrah
- Division of Biological Sciences, The University of Montana, Missoula, Montana 59812
| | - Christian H. Eggers
- Department of Biomedical Sciences, Quinnipiac University, Hamden, Connecticut 06518
| | - D. Scott Samuels
- Division of Biological Sciences, The University of Montana, Missoula, Montana 59812
- Center for Biomolecular Structure and Dynamics, The University of Montana, Missoula, Montana 59812
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30
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Borrelia burgdorferi cp32 BpaB modulates expression of the prophage NucP nuclease and SsbP single-stranded DNA-binding protein. J Bacteriol 2012; 194:4570-8. [PMID: 22730122 DOI: 10.1128/jb.00661-12] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The Borrelia burgdorferi BpaB proteins of the spirochete's ubiquitous cp32 prophages are DNA-binding proteins, required both for maintenance of the bacteriophage episomes and for transcriptional regulation of the cp32 erp operons. Through use of DNase I footprinting, we demonstrate that BpaB binds the erp operator initially at the sequence 5'-TTATA-3'. Electrophoretic mobility shift assays indicated that BpaB also binds with high affinity to sites located in the 5' noncoding regions of two additional cp32 genes. Characterization of the proteins encoded by those genes indicated that they are a single-stranded DNA-binding protein and a nuclease, which we named SsbP and NucP, respectively. Chromatin immunoprecipitation indicated that BpaB binds erp, ssbP, and nucP in live B. burgdorferi. A mutant bacterium that overexpressed BpaB produced significantly higher levels of ssbP and nucP transcript than did the wild-type parent.
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31
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Contribution of the infection-associated complement regulator-acquiring surface protein 4 (ErpC) to complement resistance of Borrelia burgdorferi. Clin Dev Immunol 2012; 2012:349657. [PMID: 22400034 PMCID: PMC3287035 DOI: 10.1155/2012/349657] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Accepted: 10/05/2011] [Indexed: 11/17/2022]
Abstract
Borrelia burgdorferi evades complement-mediated killing by interacting with complement regulators through distinct complement regulator-acquiring surface proteins (CRASPs). Here, we extend our analyses to the contribution of CRASP-4 in mediating complement resistance of B. burgdorferi and its interaction with human complement regulators. CRASP-4 (also known as ErpC) was immobilized onto magnetic beads and used to capture proteins from human serum. Following Western blotting, factor H (CFH), CFH-related protein 1 (CFHR1), CFHR2, and CFHR5 were identified as ligands of CRASP-4. To analyze the impact of native CRASP-4 on mediating survival of serum-sensitive cells in human serum, a B. garinii strain was generated that ectopically expresses CRASP-4. CRASP-4-producing bacteria bound CFHR1, CFHR2, and CFHR5 but not CFH. In addition, transformed spirochetes deposited significant amounts of lethal complement components on their surface and were susceptible to human serum, thus indicating that CRASP-4 plays a subordinate role in complement resistance of B. burgdorferi.
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32
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BpaB and EbfC DNA-binding proteins regulate production of the Lyme disease spirochete's infection-associated Erp surface proteins. J Bacteriol 2011; 194:778-86. [PMID: 22155777 DOI: 10.1128/jb.06394-11] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vector-borne pathogens regulate their protein expression profiles, producing factors during host infection that differ from those produced during vector colonization. The Lyme disease agent, Borrelia burgdorferi, produces Erp surface proteins throughout mammalian infection and represses their synthesis during colonization of vector ticks. Known functions of Erp proteins include binding of host laminin, plasmin(ogen), and regulators of complement activation. A DNA region immediately 5' of erp operons, the erp operator, is required for transcriptional regulation. The B. burgdorferi BpaB and EbfC proteins exhibit high in vitro affinities for erp operator DNA. In the present studies, chromatin immunoprecipitation (ChIP) demonstrated that both proteins bind erp operator DNA in vivo. Additionally, a combination of in vivo and in vitro methods demonstrated that BpaB functions as a repressor of erp transcription, while EbfC functions as an antirepressor.
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33
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Yang X, Promnares K, Qin J, He M, Shroder DY, Kariu T, Wang Y, Pal U. Characterization of multiprotein complexes of the Borrelia burgdorferi outer membrane vesicles. J Proteome Res 2011; 10:4556-66. [PMID: 21875077 DOI: 10.1021/pr200395b] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Among bacterial cell envelopes, the Borrelia burgdorferi outer membrane (OM) is structurally unique in that the identities of many protein complexes remain unknown; however, their characterization is the first step toward our understanding of membrane protein interactions and potential functions. Here, we used two-dimensional blue native/SDS-PAGE/mass spectrometric analysis for a global characterization of protein-protein interactions as well as to identify protein complexes in OM vesicles isolated from multiple infectious sensu stricto isolates of B. burgdorferi. Although we uncovered the existence of at least 10 distinct OM complexes harboring several unique subunits, the complexome is dominated by the frequent occurrence of a limited diversity of membrane proteins, most notably P13, outer surface protein (Osp) A, -B, -C, and -D and Lp6.6. The occurrence of these complexes and specificity of subunit interaction were further supported by independent two-dimensional immunoblotting and coimmunoprecipitation assays as well as by mutagenesis studies, where targeted depletion of a subunit member (P66) selectively abolished a specific complex. Although a comparable profile of the OM complexome was detected in two major infectious isolates, such as B31 and 297, certain complexes are likely to occur in an isolate-specific manner. Further assessment of protein complexes in multiple Osp-deficient isolates showed loss of several protein complexes but revealed the existence of additional complex/subunits that are undetectable in wild-type cells. Together, these observations uncovered borrelial antigens involved in membrane protein interactions. The study also suggests that the assembly process of OM complexes is specific and that the core or stabilizing subunits vary between complexes. Further characterization of these protein complexes including elucidation of their biological significance may shed new light on the mechanism of pathogen persistence and the development of preventative measures against the infection.
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Affiliation(s)
- Xiuli Yang
- Department of Veterinary Medicine, University of Maryland , College Park and Virginia-Maryland Regional College of Veterinary Medicine, United States
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34
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The Borrelia burgdorferi integrin ligand P66 affects gene expression by human cells in culture. Infect Immun 2011; 79:3249-61. [PMID: 21576330 DOI: 10.1128/iai.05122-11] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Borrelia burgdorferi, an agent of Lyme disease, establishes persistent infection in immunocompetent animals and humans. Although the infection in humans can be cleared by antibiotic therapy, persistence in reservoir animals is necessary for the maintenance of the bacterium in the natural reservoir host⇔tick vector infectious cycle. B. burgdorferi binds to β(1)- and β(3)-chain integrins, and the P66 outer membrane protein is responsible for at least some of the integrin binding activity of the spirochete. Because integrins are transmembrane, bidirectional signaling molecules, integrin binding may alter the nature of the host response to the bacteria. We used isogenic B. burgdorferi p66(+) and Δp66 strains to analyze the responses of cultured human cells to P66-integrin interaction during infection. Microarray results suggest that the response differs according to the cell type, infection time, and experimental conditions. Clusters of genes in functionally related categories that showed significant changes included proteins involved in cell-extracellular matrix interactions, actin dynamics, stress response, and immune responses. Integrin binding by P66 may therefore help B. burgdorferi establish infection by facilitating tissue invasion and modulating the activation of the immune system to other components of the bacteria, e.g., lipoproteins. These results provide insight into how B. burgdorferi is able to establish infection in immunocompetent hosts.
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35
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Siegel C, Hallström T, Skerka C, Eberhardt H, Uzonyi B, Beckhaus T, Karas M, Wallich R, Stevenson B, Zipfel PF, Kraiczy P. Complement factor H-related proteins CFHR2 and CFHR5 represent novel ligands for the infection-associated CRASP proteins of Borrelia burgdorferi. PLoS One 2010; 5:e13519. [PMID: 20975954 PMCID: PMC2958145 DOI: 10.1371/journal.pone.0013519] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Accepted: 09/21/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND One virulence property of Borrelia burgdorferi is its resistance to innate immunity, in particular to complement-mediated killing. Serum-resistant B. burgdorferi express up to five distinct complement regulator-acquiring surface proteins (CRASP) which interact with complement regulator factor H (CFH) and factor H-like protein 1 (FHL1) or factor H-related protein 1 (CFHR1). In the present study we elucidate the role of the infection-associated CRASP-3 and CRASP-5 protein to serve as ligands for additional complement regulatory proteins as well as for complement resistance of B. burgdorferi. METHODOLOGY/PRINCIPAL FINDINGS To elucidate whether CRASP-5 and CRASP-3 interact with various human proteins, both borrelial proteins were immobilized on magnetic beads. Following incubation with human serum, bound proteins were eluted and separated by Glycine-SDS-PAGE. In addition to CFH and CFHR1, complement regulators CFHR2 and CFHR5 were identified as novel ligands for both borrelial proteins by employing MALDI-TOF. To further assess the contributions of CRASP-3 and CRASP-5 to complement resistance, a serum-sensitive B. garinii strain G1 which lacks all CFH-binding proteins was used as a valuable model for functional analyses. Both CRASPs expressed on the B. garinii outer surface bound CFH as well as CFHR1 and CFHR2 in ELISA. In contrast, live B. garinii bound CFHR1, CFHR2, and CFHR5 and only miniscute amounts of CFH as demonstrated by serum adsorption assays and FACS analyses. Further functional analysis revealed that upon NHS incubation, CRASP-3 or CRASP-5 expressing borreliae were killed by complement. CONCLUSIONS/SIGNIFICANCE In the absence of CFH and the presence of CFHR1, CFHR2 and CFHR5, assembly and integration of the membrane attack complex was not efficiently inhibited indicating that CFH in co-operation with CFHR1, CFHR2 and CFHR5 supports complement evasion of B. burgdorferi.
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Affiliation(s)
- Corinna Siegel
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Frankfurt/Main, Germany
| | - Teresia Hallström
- Department of Infection Biology, Leibniz-Institute for Natural Products Research and Infection Biology, Jena, Germany
| | - Christine Skerka
- Department of Infection Biology, Leibniz-Institute for Natural Products Research and Infection Biology, Jena, Germany
| | - Hannes Eberhardt
- Department of Infection Biology, Leibniz-Institute for Natural Products Research and Infection Biology, Jena, Germany
| | - Barbara Uzonyi
- Department of Infection Biology, Leibniz-Institute for Natural Products Research and Infection Biology, Jena, Germany
| | - Tobias Beckhaus
- Institute of Pharmaceutical Chemistry, Johann Wolfgang Goethe-University, Frankfurt/Main, Germany
| | - Michael Karas
- Institute of Pharmaceutical Chemistry, Johann Wolfgang Goethe-University, Frankfurt/Main, Germany
| | - Reinhard Wallich
- Institute of Immunology, University of Heidelberg, Heidelberg, Germany
| | - Brian Stevenson
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, Kentucky, United States of America
| | - Peter F. Zipfel
- Department of Infection Biology, Leibniz-Institute for Natural Products Research and Infection Biology, Jena, Germany
- Friedrich Schiller University, Jena, Germany
| | - Peter Kraiczy
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Frankfurt/Main, Germany
- * E-mail:
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36
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Inadequate binding of immune regulator factor H is associated with sensitivity of Borrelia lusitaniae to human complement. Infect Immun 2010; 78:4467-76. [PMID: 20823202 DOI: 10.1128/iai.00138-10] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Spirochetes belonging to the Borrelia burgdorferi sensu lato complex differ in resistance to complement-mediated killing by human serum. Here, we characterize complement sensitivity of a panel of B. lusitaniae isolates derived from ticks collected in Germany and Portugal as well as one patient-derived isolate, PoHL. All isolates are highly susceptible to complement-mediated lysis in human serum and activate complement predominantly by the alternative pathway, leading to an increased deposition of complement components C3, C6, and the terminal complement complex. Interestingly, serum-sensitive B. lusitaniae isolates were able to bind immune regulator factor H (CFH), and some strains also bound CFH-related protein 1 (CFHR1) and CFHR2. Moreover, CFH bound to the surface of B. lusitaniae was inefficient in mediating C3b conversion. Furthermore, the identification and characterization of a potential CFH-binding protein, OspE, revealed that this molecule possesses a significantly reduced binding capacity for CFH compared to that of CFH-binding OspE paralogs expressed by various serum-resistant Borrelia species. This finding suggests that a reduced binding capability of CFH is associated with an increased serum sensitivity of B. lusitaniae to human complement.
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37
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Earnhart CG, Leblanc DV, Alix KE, Desrosiers DC, Radolf JD, Marconi RT. Identification of residues within ligand-binding domain 1 (LBD1) of the Borrelia burgdorferi OspC protein required for function in the mammalian environment. Mol Microbiol 2010; 76:393-408. [PMID: 20199597 DOI: 10.1111/j.1365-2958.2010.07103.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Borrelia burgdorferi outer surface protein C (ospC) is required for the establishment of infection in mammals. However, its precise function remains controversial. The biologically active form of OspC appears to be a homodimer. Alpha helix 1 and 1' of the apposing monomers form a solvent-accessible pocket at the dimeric interface that presents a putative ligand-binding domain (LBD1). Here we employ site-directed and allelic-exchange mutagenesis to test the hypothesis that LBD1 is a determinant of OspC function in the mammalian environment. Substitution of residues K60, E61 and E63 which line LBD1 resulted in the loss of infectivity or influenced dissemination. Analyses of the corresponding recombinant proteins demonstrated that the loss of function was not due to structural perturbation, impaired dimer formation or the loss of plasminogen binding. This study is the first to assess the involvement of individual residues and domains of OspC in its in vivo function. The data support the hypothesis that OspC interacts with a mammalian derived ligand that is critical for survival during early infection. These results shed new light on the structure-functions relationships of OspC and challenge existing hypotheses regarding OspC function in mammals.
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Affiliation(s)
- Christopher G Earnhart
- Department of Microbiology and Immunology, Medical College of Virginia at Virginia Commonwealth University, Richmond, VA, USA
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38
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Functional characterization of Borrelia spielmanii outer surface proteins that interact with distinct members of the human factor H protein family and with plasminogen. Infect Immun 2009; 78:39-48. [PMID: 19858303 DOI: 10.1128/iai.00691-09] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acquisition of complement regulator factor H (CFH) and factor H-like protein 1 (CFHL1) from human serum enables Borrelia spielmanii, one of the etiological agents of Lyme disease, to evade complement-mediated killing by the human host. Up to three distinct complement regulator-acquiring surface proteins (CRASPs) may be expressed by serum-resistant B. spielmanii, each exhibiting an affinity for CFH and/or CFHL1. Here, we describe the functional characterization of the 15-kDa CRASPs of B. spielmanii, members of the polymorphic Erp (OspE/F-related) protein family, that bind two distinct host complement regulators, CFH and factor H-related protein 1 (CFHR1), but not CFHL1. CFH bound to the B. spielmanii CRASPs maintained cofactor activity for factor I-mediated C3b inactivation. Three naturally occurring alleles of this protein bound CFH and CFHR1 while a fourth natural allele could not. Comparative sequence analysis of these protein alleles identified a single amino acid, histidine-79, as playing a significant role in CFH/CFHR1 binding, with substitution by an arginine completely abrogating ligand binding. The mutation of His-79 to Arg did not inhibit binding of plasminogen, another known ligand of this group of borrelial outer-surface proteins.
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CspA-mediated binding of human factor H inhibits complement deposition and confers serum resistance in Borrelia burgdorferi. Infect Immun 2009; 77:2773-82. [PMID: 19451251 DOI: 10.1128/iai.00318-09] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Borrelia burgdorferi has developed efficient mechanisms for evading the innate immune response during mammalian infection and has been shown to be resistant to the complement-mediated bactericidal activity of human serum. It is well recognized that B. burgdorferi expresses multiple lipoproteins on its surface that bind the human complement inhibitors factor H and factor H-like protein 1 (FH/FHL-1). The binding of FH/FHL-1 on the surface of B. burgdorferi is thought to enhance its ability to evade serum-mediated killing during the acute phase of infection. One of the key B. burgdorferi FH/FHL-1 binding proteins identified thus far was designated CspA. While it is known that CspA binds FH/FHL-1, it is unclear how the interaction between CspA and FH/FHL-1 specifically enhances serum resistance. To better understand how CspA mediates serum resistance in B. burgdorferi, we inactivated cspA in a virulent strain of B. burgdorferi. An affinity ligand blot immunoassay and indirect immunofluorescence revealed that the CspA mutant does not efficiently bind human FH to its surface. Consistent with the lack of FH binding, the CspA mutant was also highly sensitive to killing by human serum. Additionally, the deposition of complement components C3, C6, and C5b-9 was enhanced on the surface of the CspA mutant compared to that of the wild-type strain. The combined data lead us to conclude that the CspA-mediated binding of human FH confers serum resistance by directly inhibiting complement deposition on the surface of B. burgdorferi.
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Rogers EA, Terekhova D, Zhang HM, Hovis KM, Schwartz I, Marconi RT. Rrp1, a cyclic-di-GMP-producing response regulator, is an important regulator of Borrelia burgdorferi core cellular functions. Mol Microbiol 2009; 71:1551-73. [PMID: 19210621 DOI: 10.1111/j.1365-2958.2009.06621.x] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Two-component systems (TCS) are universal among bacteria and play critical roles in gene regulation. Our understanding of the contributions of TCS in the biology of the Borrelia is just now beginning to develop. Borrelia burgdorferi, a causative agent of Lyme disease, harbours a TCS comprised of open reading frames (ORFs) BB0419 and BB0420. BB0419 encodes a response regulator designated Rrp1, and BB0420 encodes a hybrid histidine kinase-response regulator designated Hpk1. Rrp1, which contains a conserved GGDEF domain, undergoes phosphorylation and produces the secondary messenger, cyclic diguanylate (c-di-GMP), a critical signaling molecule in numerous organisms. However, the regulatory role of the Rrp1-Hpk1 TCS and c-di-GMP signaling in Borrelia biology are unexplored. In this study, the distribution, conservation, expression and potential global regulatory capability of Rrp1 were assessed. rrp1 was found to be universal and highly conserved among isolates, co-transcribed with hpk1, constitutively expressed during in vitro cultivation, and significantly upregulated upon tick feeding. Allelic exchange replacement and microarray analyses revealed that the Rrp1 regulon consists of a large number of genes encoded by the core Borrelia genome (linear chromosome, linear plasmid 54 and circular plasmid 26) that encode for proteins involved in central metabolic processes and virulence mechanisms including immune evasion.
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Affiliation(s)
- Elizabeth A Rogers
- Department of Microbiology and Immunology, Medical College of Virginia Commonwealth University, Richmond, VA, USA
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Lu L, Ma Z, Jokiranta TS, Whitney AR, DeLeo FR, Zhang JR. Species-specific interaction of Streptococcus pneumoniae with human complement factor H. THE JOURNAL OF IMMUNOLOGY 2008; 181:7138-46. [PMID: 18981135 DOI: 10.4049/jimmunol.181.10.7138] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Streptococcus pneumoniae naturally colonizes the nasopharynx as a commensal organism and sometimes causes infections in remote tissue sites. This bacterium is highly capable of resisting host innate immunity during nasopharyngeal colonization and disseminating infections. The ability to recruit complement factor H (FH) by S. pneumoniae has been implicated as a bacterial immune evasion mechanism against complement-mediated bacterial clearance because FH is a complement alternative pathway inhibitor. S. pneumoniae recruits FH through a previously defined FH binding domain of choline-binding protein A (CbpA), a major surface protein of S. pneumoniae. In this study, we show that CbpA binds to human FH, but not to the FH proteins of mouse and other animal species tested to date. Accordingly, deleting the FH binding domain of CbpA in strain D39 did not result in obvious change in the levels of pneumococcal bacteremia or virulence in a bacteremia mouse model. Furthermore, this species-specific pneumococcal interaction with FH was shown to occur in multiple pneumococcal isolates from the blood and cerebrospinal fluid. Finally, our phagocytosis experiments with human and mouse phagocytes and complement systems provide additional evidence to support our hypothesis that CbpA acts as a bacterial determinant for pneumococcal resistance to complement-mediated host defense in humans.
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Affiliation(s)
- Ling Lu
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, NY 12208, USA
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42
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Coleman AS, Yang X, Kumar M, Zhang X, Promnares K, Shroder D, Kenedy MR, Anderson JF, Akins DR, Pal U. Borrelia burgdorferi complement regulator-acquiring surface protein 2 does not contribute to complement resistance or host infectivity. PLoS One 2008; 3:3010e. [PMID: 18714378 PMCID: PMC2526170 DOI: 10.1371/journal.pone.0003010] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Accepted: 07/30/2008] [Indexed: 11/20/2022] Open
Abstract
Borrelia burgdorferi, the pathogen of Lyme disease, cycles in nature through Ixodes ticks and mammalian hosts. At least five Complement Regulator-Acquiring Surface Proteins (BbCRASPs) are produced by B. burgdorferi, which are thought to assist spirochetes in host immune evasion. Recent studies established that BbCRASP-2 is preferentially expressed in mammals, and elicits robust antibody response in infected hosts, including humans. We show that BbCRASP-2 is ubiquitously expressed in diverse murine tissues, but not in ticks, reinforcing a role of BbCRASP-2 in conferring B. burgdorferi defense against persistent host immune threats, such as complement. BbCRASP-2 immunization, however, fails to protect mice from B. burgdorferi infection and does not modify disease, as reflected by the development of arthritis. An infectious BbCRASP-2 mutant was generated, therefore, to examine the precise role of the gene product in spirochete infectivity. Similar to wild type B. burgdorferi, BbCRASP-2 mutants remain insensitive to complement-mediated killing in vitro, retain full murine infectivity and induce arthritis. Quantitative RT-PCR assessment indicates that survivability of BbCRASP-2-deficient B. burgdorferi is not due to altered expression of other BbCRASPs. Together, these results suggest that the function of a selectively expressed B. burgdorferi gene, BbCRASP-2, is not essential for complement resistance or infectivity in the murine host.
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Affiliation(s)
- Adam S. Coleman
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, United States of America
| | - Xiuli Yang
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, United States of America
| | - Manish Kumar
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, United States of America
| | - Xinyue Zhang
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, United States of America
| | - Kamoltip Promnares
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, United States of America
| | - Deborah Shroder
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, United States of America
| | - Melisha R. Kenedy
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - John F. Anderson
- Department of Entomology, Connecticut Agricultural Experiment Station, New Haven, Connecticut, United States of America
| | - Darrin R. Akins
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Utpal Pal
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, United States of America
- * E-mail:
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Welsch JA, Ram S, Koeberling O, Granoff DM. Complement-dependent synergistic bactericidal activity of antibodies against factor H-binding protein, a sparsely distributed meningococcal vaccine antigen. J Infect Dis 2008; 197:1053-61. [PMID: 18419542 DOI: 10.1086/528994] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Antibodies to factor H (fH)-binding protein (fHBP), a meningococcal vaccine antigen, activate classical complement pathway serum bactericidal activity (SBA) and block binding of the complement inhibitor fH. METHODS To understand these 2 functions in protection, we investigated the interactions of human complement and 2 anti-fHBP monoclonal antibodies (MAbs) with encapsulated Neisseria meningitidis. RESULTS JAR 3 (IgG3) blocks fH binding and elicits SBA against 2 strains with naturally high fHBP expression and a low-expressing strain genetically engineered to express high fHBP levels. JAR 4 (IgG2a) does not block fH binding or elicit SBA. Neither MAb alone elicits SBA against 2 other strains with low fHBP expression, but together the MAbs increase C4b binding and elicit SBA; JAR 3 alone also is bactericidal in whole blood. In nonimmune blood, fHBP knockout mutants from high-expressing stains do not survive, but mutants of low-expressing strains do. CONCLUSIONS Expression of fHBP is a prerequisite for bacterial survival in blood only by strains with naturally high fHBP expression. In low-expressing strains, combinations of 2 nonbactericidal anti-fHBP MAbs can bind to nonoverlapping epitopes, engage C1q, activate C4, and mediate classical complement pathway SBA. In the absence of sufficient C4b binding for SBA, an individual MAb can have opsonophagocytic bactericidal activity.
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Affiliation(s)
- Jo Anne Welsch
- Center for Immunobiology and Vaccine Development, Children's Hospital Oakland Research Institute, Oakland, California, USA
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Identification of an antiparallel coiled-coil/loop domain required for ligand binding by the Borrelia hermsii FhbA protein: additional evidence for the role of FhbA in the host-pathogen interaction. Infect Immun 2008; 76:2113-22. [PMID: 18299341 DOI: 10.1128/iai.01266-07] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Borrelia hermsii, an etiological agent of tick-borne relapsing fever in North America, binds host-derived serum proteins including factor H (FH), plasminogen, and an unidentified 60-kDa protein via its FhbA protein. Two distinct phylogenetic types of FhbA have been delineated (FhbA1 and FhbA2). These orthologs share a conserved C-terminal domain that contains two alpha helices with a high predictive probability of coiled-coil formation that are separated by a 14-amino-acid loop domain. Through site-directed mutagenesis, we have identified residues within these domains that influence the binding of both mouse and human FH, plasminogen, and/or the 60-kDa protein. To further investigate the involvement of FhbA in the host-pathogen interaction, strains that are either FhbA(+) (isolate YOR) or FhbA(-) (isolate REN) were tested for serum sensitivity. Significant differences were observed, with YOR and REN being serum resistant and serum sensitive (intermediate), respectively. To test the abilities of these strains to infect and persist in mice, mice were needle inoculated, and infectivity and persistence were then assessed. While both strains REN and YOR infected mice, only the FhbA(+) YOR strain persisted beyond day 4. Survival of the YOR isolate in blood correlated with the upregulation of the fhbA gene, as demonstrated by real-time reverse transcriptase PCR. These data advance our understanding of the unique interactions of FhbA with individual serum proteins and provide support for the hypothesis that FhbA is an important contributor to the pathogenesis of the relapsing fever spirochete B. hermsii.
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Brissette CA, Cooley AE, Burns LH, Riley SP, Verma A, Woodman ME, Bykowski T, Stevenson B. Lyme borreliosis spirochete Erp proteins, their known host ligands, and potential roles in mammalian infection. Int J Med Microbiol 2008; 298 Suppl 1:257-67. [PMID: 18248770 DOI: 10.1016/j.ijmm.2007.09.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/04/2007] [Indexed: 10/22/2022] Open
Abstract
Lyme borreliae naturally maintain numerous distinct DNA elements of the cp32 family, each of which carries a mono- or bicistronic erp locus. The encoded Erp proteins are surface-exposed outer membrane lipoproteins that are produced at high levels during mammalian infection but largely repressed during colonization of vector ticks. Recent studies have revealed that some Erp proteins can serve as bacterial adhesins, binding host proteins such as the complement regulator factor H and the extracellular matrix component laminin. These results suggest that Erp proteins play roles in multiple aspects of mammalian infection.
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Affiliation(s)
- Catherine A Brissette
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, College of Medicine, MS 421 Chandler Medical Center, Lexington, KY 40536-0298, USA
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46
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The Important and Diverse Roles of Antibodies in the Host Response to Borrelia Infections. Curr Top Microbiol Immunol 2008; 319:63-103. [DOI: 10.1007/978-3-540-73900-5_4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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47
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Rogers EA, Marconi RT. Delineation of species-specific binding properties of the CspZ protein (BBH06) of Lyme disease spirochetes: evidence for new contributions to the pathogenesis of Borrelia spp. Infect Immun 2007; 75:5272-81. [PMID: 17846117 PMCID: PMC2168308 DOI: 10.1128/iai.00850-07] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Borrelia burgdorferi CspZ (TIGR open reading frame designation, BBH06) is part of a functionally related group of proteins that bind one or more members of the factor H (FH) protein family. In this report we assess the conservation, distribution, properties, and ligand binding abilities of CspZ from the three main Borrelia species associated with Lyme disease infections in humans. CspZ (also referred to as BbCRASP-2 in the literature) was found to be highly conserved at the intraspecies level but divergent at the interspecies level. All CspZ orthologs that originated from B. burgdorferi isolates bound FH from a diverse group of mammals. In contrast, CspZ derived from B. garinii and B. afzelii did not. Regardless of the Borrelia species of origin, all CspZ proteins tested bound to unknown approximately 60-kDa serum proteins produced by different mammals. To further define the molecular basis for the differential binding of CspZ orthologs to host proteins, DNA sequence, truncation, and site-directed mutagenesis analyses were performed. DNA sequence analyses revealed that B. garinii and B. afzelii CspZ orthologs possess a 64-amino-acid N-terminal domain that is absent from B. burgdorferi CspZ. However, binding analyses of recombinant proteins revealed that this domain does not in and of itself influence ligand binding properties. Truncation and mutagenesis analyses further revealed that the key determinants required for ligand binding are discontinuous and that the presentation of the ligand binding pocket is dependent on alpha helices with high coiled-coil formation probability. The data presented here provide insight into the molecular basis of CspZ-ligand interactions and suggest that CspZ orthologs from diverse Borrelia species can contribute to the host-pathogen interaction through their interaction with serum proteins.
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Affiliation(s)
- Elizabeth A Rogers
- Department of Microbiology and Immunology, Medical College of Virginia at Virginia Commonwealth University, Richmond, VA 23298-0678, USA
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48
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Bykowski T, Woodman ME, Cooley AE, Brissette CA, Brade V, Wallich R, Kraiczy P, Stevenson B. Coordinated expression of Borrelia burgdorferi complement regulator-acquiring surface proteins during the Lyme disease spirochete's mammal-tick infection cycle. Infect Immun 2007; 75:4227-36. [PMID: 17562769 PMCID: PMC1951152 DOI: 10.1128/iai.00604-07] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Revised: 05/23/2007] [Accepted: 06/01/2007] [Indexed: 11/20/2022] Open
Abstract
The Lyme disease spirochete, Borrelia burgdorferi, is largely resistant to being killed by its hosts' alternative complement activation pathway. One possible resistance mechanism of these bacteria is to coat their surfaces with host complement regulators, such as factor H. Five different B. burgdorferi outer surface proteins having affinities for factor H have been identified: complement regulator-acquiring surface protein 1 (BbCRASP-1), encoded by cspA; BbCRASP-2, encoded by cspZ; and three closely related proteins, BbCRASP-3, -4, and -5, encoded by erpP, erpC, and erpA, respectively. We now present analyses of the recently identified BbCRASP-2 and cspZ expression patterns throughout the B. burgdorferi infectious cycle, plus novel analyses of BbCRASP-1 and erp-encoded BbCRASPs. Our results, combined with data from earlier studies, indicate that BbCRASP-2 is produced primarily during established mammalian infection, while BbCRASP-1 is produced during tick-to-mammal and mammal-to-tick transmission stages but not during established mammalian infection, and Erp-BbCRASPs are produced from the time of transmission from infected ticks into mammals until they are later acquired by other feeding ticks. Transcription of cspZ and synthesis of BbCRASP-2 were severely repressed during cultivation in laboratory medium relative to mRNA levels observed during mammalian infection, and cspZ expression was influenced by culture temperature and pH, observations which will assist identification of the mechanisms employed by B. burgdorferi to control expression of this borrelial infection-associated protein.
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Affiliation(s)
- Tomasz Bykowski
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, MS 421 W.R. Willard Medical Education Building, 800 Rose Street, Lexington, KY 40536-0298, USA
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49
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Cabello FC, Godfrey HP, Newman SA. Hidden in plain sight: Borrelia burgdorferi and the extracellular matrix. Trends Microbiol 2007; 15:350-4. [PMID: 17600717 DOI: 10.1016/j.tim.2007.06.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Accepted: 06/13/2007] [Indexed: 10/23/2022]
Abstract
Borrelia burgdorferi, the tick-transmitted etiologic agent of Lyme borreliosis, can colonize and persist in multiple tissue sites despite vigorous host immune responses. The extracellular matrix appears to provide a protective niche for the spirochete. Recent studies in mice suggest that B. burgdorferi interacts in various ways with collagen and its associated molecules, exploiting molecular and structural features to establish microcolonial refugia. Better knowledge of the genetic and structural bases for these interactions of B. burgdorferi with the extracellular matrix will be required before an understanding of the persistence of B. burgdorferi in the tissues and development of chronic infections can be achieved.
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Affiliation(s)
- Felipe C Cabello
- Department of Microbiology and Immunology, New York Medical College, Valhalla, NY 10595, USA.
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50
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Woodman ME, Cooley AE, Miller JC, Lazarus JJ, Tucker K, Bykowski T, Botto M, Hellwage J, Wooten RM, Stevenson B. Borrelia burgdorferi binding of host complement regulator factor H is not required for efficient mammalian infection. Infect Immun 2007; 75:3131-9. [PMID: 17420242 PMCID: PMC1932899 DOI: 10.1128/iai.01923-06] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The causative agent of Lyme disease, Borrelia burgdorferi, is naturally resistant to its host's alternative pathway of complement-mediated killing. Several different borrelial outer surface proteins have been identified as being able to bind host factor H, a regulator of the alternative pathway, leading to a hypothesis that such binding is important for borrelial resistance to complement. To test this hypothesis, the development of B. burgdorferi infection was compared between factor H-deficient and wild-type mice. Factor B- and C3-deficient mice were also studied to determine the relative roles of the alternative and classical/lectin pathways in B. burgdorferi survival during mammalian infection. While it was predicted that B. burgdorferi should be impaired in its ability to infect factor H-deficient animals, quantitative analyses of bacterial loads indicated that those mice were infected at levels similar to those of wild-type and factor B- and C3-deficient mice. Ticks fed on infected factor H-deficient or wild-type mice all acquired similar numbers of bacteria. Indirect immunofluorescence analysis of B. burgdorferi acquired by feeding ticks from the blood of infected mice indicated that none of the bacteria had detectable levels of factor H on their outer surfaces, even though such bacteria express high levels of surface proteins capable of binding factor H. These findings demonstrate that the acquisition of host factor H is not essential for mammalian infection by B. burgdorferi and indicate that additional mechanisms are employed by the Lyme disease spirochete to evade complement-mediated killing.
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Affiliation(s)
- Michael E Woodman
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, MS421 W. R. Willard Medical Education Building, Lexington, KY 40536-0298, USA
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