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Abstract
Relapsing fever (RF) is caused by several species of Borrelia; all, except two species, are transmitted to humans by soft (argasid) ticks. The species B. recurrentis is transmitted from one human to another by the body louse, while B. miyamotoi is vectored by hard-bodied ixodid tick species. RF Borrelia have several pathogenic features that facilitate invasion and dissemination in the infected host. In this article we discuss the dynamics of vector acquisition and subsequent transmission of RF Borrelia to their vertebrate hosts. We also review taxonomic challenges for RF Borrelia as new species have been isolated throughout the globe. Moreover, aspects of pathogenesis including symptomology, neurotropism, erythrocyte and platelet adhesion are discussed. We expound on RF Borrelia evasion strategies for innate and adaptive immunity, focusing on the most fundamental pathogenetic attributes, multiphasic antigenic variation. Lastly, we review new and emerging species of RF Borrelia and discuss future directions for this global disease.
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Affiliation(s)
- Job Lopez
- Department of Pediatrics, Section of Tropical Medicine, Baylor College of Medicine and Texas Children's Hospital, Houston TX, USA
| | - Joppe W Hovius
- Center for Experimental and Molecular Medicine, Amsterdam Medical centers, location Academic Medical Center, University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands
| | - Sven Bergström
- Department of Molecular Biology, Umeå Center for Microbial Research, Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
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2
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O'Bier NS, Hatke AL, Camire AC, Marconi RT. Human and Veterinary Vaccines for Lyme Disease. Curr Issues Mol Biol 2020; 42:191-222. [PMID: 33289681 DOI: 10.21775/cimb.042.191] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Lyme disease (LD) is an emerging zoonotic infection that is increasing in incidence in North America, Europe, and Asia. With the development of safe and efficacious vaccines, LD can potentially be prevented. Vaccination offers a cost-effective and safe approach for decreasing the risk of infection. While LD vaccines have been widely used in veterinary medicine, they are not available as a preventive tool for humans. Central to the development of effective vaccines is an understanding of the enzootic cycle of LD, differential gene expression of Borrelia burgdorferi in response to environmental variables, and the genetic and antigenic diversity of the unique bacteria that cause this debilitating disease. Here we review these areas as they pertain to past and present efforts to develop human, veterinary, and reservoir targeting LD vaccines. In addition, we offer a brief overview of additional preventative measures that should employed in conjunction with vaccination.
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Affiliation(s)
- Nathaniel S O'Bier
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA 23298, USA
| | - Amanda L Hatke
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA 23298, USA
| | - Andrew C Camire
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA 23298, USA
| | - Richard T Marconi
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA 23298, USA
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Röttgerding F, Kraiczy P. Immune Evasion Strategies of Relapsing Fever Spirochetes. Front Immunol 2020; 11:1560. [PMID: 32793216 PMCID: PMC7390862 DOI: 10.3389/fimmu.2020.01560] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 06/12/2020] [Indexed: 12/13/2022] Open
Abstract
Relapsing fever (RF) is claimed a neglected arthropod-borne disease caused by a number of diverse human pathogenic Borrelia (B.) species. These RF borreliae are separated into the groups of tick-transmitted species including B. duttonii, B. hermsii, B. parkeri, B. turicatae, B. hispanica, B. persica, B. caucasica, and B. myiamotoi, and the louse-borne Borrelia species B. recurrentis. As typical blood-borne pathogens achieving high cell concentrations in human blood, RF borreliae (RFB) must outwit innate immunity, in particular complement as the first line of defense. One prominent strategy developed by RFB to evade innate immunity involves inactivation of complement by recruiting distinct complement regulatory proteins, e.g., C1 esterase inhibitor (C1-INH), C4b-binding protein (C4BP), factor H (FH), FH-like protein-1 (FHL-1), and factor H-related proteins FHR-1 and FHR-2, or binding of individual complement components and plasminogen, respectively. A number of multi-functional, complement and plasminogen-binding molecules from distinct Borrelia species have previously been identified and characterized, exhibiting considerable heterogeneity in their sequences, structures, gene localization, and their capacity to bind host-derived proteins. In addition, RFB possess a unique system of antigenic variation, allowing them to change the composition of surface-exposed variable major proteins, thus evading the acquired immune response of the human host. This review focuses on the current knowledge of the immune evasion strategies by RFB and highlights the role of complement-interfering and infection-associated molecules for the pathogenesis of RFB.
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Affiliation(s)
- Florian Röttgerding
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Goethe University Frankfurt, Frankfurt, Germany
| | - Peter Kraiczy
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Goethe University Frankfurt, Frankfurt, Germany
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4
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Structural determination of the complement inhibitory domain of Borrelia burgdorferi BBK32 provides insight into classical pathway complement evasion by Lyme disease spirochetes. PLoS Pathog 2019; 15:e1007659. [PMID: 30897158 PMCID: PMC6445466 DOI: 10.1371/journal.ppat.1007659] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 04/02/2019] [Accepted: 02/26/2019] [Indexed: 01/07/2023] Open
Abstract
The carboxy-terminal domain of the BBK32 protein from Borrelia burgdorferi sensu stricto, termed BBK32-C, binds and inhibits the initiating serine protease of the human classical complement pathway, C1r. In this study we investigated the function of BBK32 orthologues of the Lyme-associated Borrelia burgdorferi sensu lato complex, designated BAD16 from B. afzelii strain PGau and BGD19 from B. garinii strain IP90. Our data show that B. afzelii BAD16-C exhibits BBK32-C-like activities in all assays tested, including high-affinity binding to purified C1r protease and C1 complex, and potent inhibition of the classical complement pathway. Recombinant B. garinii BGD19-C also bound C1 and C1r with high-affinity yet exhibited significantly reduced in vitro complement inhibitory activities relative to BBK32-C or BAD16-C. Interestingly, natively produced BGD19 weakly recognized C1r relative to BBK32 and BAD16 and, unlike these proteins, BGD19 did not confer significant protection from serum killing. Site-directed mutagenesis was performed to convert BBK32-C to resemble BGD19-C at three residue positions that are identical between BBK32 and BAD16 but different in BGD19. The resulting chimeric protein was designated BXK32-C and this BBK32-C variant mimicked the properties observed for BGD19-C. To query the disparate complement inhibitory activities of BBK32 orthologues, the crystal structure of BBK32-C was solved to 1.7Å limiting resolution. BBK32-C adopts an anti-parallel four-helix bundle fold with a fifth alpha-helix protruding from the helical core. The structure revealed that the three residues targeted in the BXK32-C chimera are surface-exposed, further supporting their potential relevance in C1r binding and inhibition. Additional binding assays showed that BBK32-C only recognized C1r fragments containing the serine protease domain. The structure-function studies reported here improve our understanding of how BBK32 recognizes and inhibits C1r and provide new insight into complement evasion mechanisms of Lyme-associated spirochetes of the B. burgdorferi sensu lato complex.
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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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6
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Abstract
Blood parasites are considered some of the most significant pathogens for the conservation of penguins, due to the considerable morbidity and mortality they have been shown to produce in captive and wild populations of these birds. Parasites known to occur in the blood of penguins include haemosporidian protozoans (Plasmodium, Leucocytozoon, Haemoproteus), piroplamid protozoans (Babesia), kinetoplastid protozoans (Trypanosoma), spirochete bacteria (Borrelia) and nematode microfilariae. This review provides a critical and comprehensive assessment of the current knowledge on these parasites, providing an overview of their biology, host and geographic distribution, epidemiology, pathology and implications for public health and conservation.
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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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8
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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: 17] [Impact Index Per Article: 2.4] [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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9
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Parsons NJ, Voogt NM, Schaefer AM, Peirce MA, Vanstreels RET. Occurrence of blood parasites in seabirds admitted for rehabilitation in the Western Cape, South Africa, 2001-2013. Vet Parasitol 2016; 233:52-61. [PMID: 28043389 DOI: 10.1016/j.vetpar.2016.12.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Revised: 11/15/2016] [Accepted: 12/01/2016] [Indexed: 11/27/2022]
Abstract
Blood parasites are generally uncommon in seabirds, and knowledge on their epidemiology is further limited by the fact that they often inhabit remote locations that are logistically difficult or expensive to study. We present a long term data set of blood smear examinations of 1909 seabirds belonging to 27 species that were admitted to a rehabilitation centre in Cape Town (Western Cape, South Africa) between 2001 and 2013. Blood parasites were detected in 59% of species (16/27) and 29% of individuals examined (551/1909). The following blood parasites were recorded: Babesia ugwidiensis, Babesia peircei, Babesia sp., Plasmodium sp., Leucocytozoon ugwidi, Hepatozoon albatrossi, Haemoproteus skuae and Spirochaetales. Several of the records are novel host-parasite associations, demonstrating the potential of rehabilitation centres for parasite and disease surveillance, particularly for species infrequently sampled from which no host-specific parasites have been described.
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Affiliation(s)
- N J Parsons
- Southern African Foundation for the Conservation of Coastal Birds (SANCCOB), P.O. Box 11116, Bloubergrant, 7443, South Africa; Bayworld Centre for Research and Education, Port Elizabeth, South Africa.
| | - N M Voogt
- Southern African Foundation for the Conservation of Coastal Birds (SANCCOB), P.O. Box 11116, Bloubergrant, 7443, South Africa
| | - A M Schaefer
- Harbor Branch Oceanographic Institution, Florida Atlantic University, 5600U.S. 1 North, Fort Pierce, FL 34946, USA
| | - M A Peirce
- MP International Consultancy, 6 Normandale House, Normandale, Bexhill-on-Sea, East Sussex, TN39 3NZ, UK; International Reference Centre for Avian Hematozoa, Queensland Museum, South Brisbane, Queensland, Australia
| | - R E T Vanstreels
- Laboratory of Wildlife Comparative Pathology (LAPCOM), University of São Paulo, Avenida Professor Orlando Marques de Paiva, 87, São Paulo, SP, 05508-270, Brazil; Marine Apex Predator Research Unit (MAPRU), Department of Zoology, Nelson Mandela Metropolitan University, Port Elizabeth, 6031, South Africa
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Borrelia burgdorferi BBK32 Inhibits the Classical Pathway by Blocking Activation of the C1 Complement Complex. PLoS Pathog 2016; 12:e1005404. [PMID: 26808924 PMCID: PMC4725857 DOI: 10.1371/journal.ppat.1005404] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 12/26/2015] [Indexed: 12/03/2022] Open
Abstract
Pathogens that traffic in blood, lymphatics, or interstitial fluids must adopt strategies to evade innate immune defenses, notably the complement system. Through recruitment of host regulators of complement to their surface, many pathogens are able to escape complement-mediated attack. The Lyme disease spirochete, Borrelia burgdorferi, produces a number of surface proteins that bind to factor H related molecules, which function as the dominant negative regulator of the alternative pathway of complement. Relatively less is known about how B. burgdorferi evades the classical pathway of complement despite the observation that some sensu lato strains are sensitive to classical pathway activation. Here we report that the borrelial lipoprotein BBK32 potently and specifically inhibits the classical pathway by binding with high affinity to the initiating C1 complex of complement. In addition, B. burgdorferi cells that produce BBK32 on their surface bind to both C1 and C1r and a serum sensitive derivative of B. burgdorferi is protected from killing via the classical pathway in a BBK32-dependent manner. Subsequent biochemical and biophysical approaches localized the anti-complement activity of BBK32 to its globular C-terminal domain. Mechanistic studies reveal that BBK32 acts by entrapping C1 in its zymogen form by binding and inhibiting the C1 subcomponent, C1r, which serves as the initiating serine protease of the classical pathway. To our knowledge this is the first report of a spirochetal protein acting as a direct inhibitor of the classical pathway and is the only example of a biomolecule capable of specifically and noncovalently inhibiting C1/C1r. By identifying a unique mode of complement evasion this study greatly enhances our understanding of how pathogens subvert and potentially manipulate host innate immune systems. The human complement system is a connected network of blood proteins capable of recognizing and eliminating microbial intruders. To avoid the destructive force of complement activation, many microorganisms that enter the bloodstream express molecules that disrupt key steps of the complement cascade by interacting with specific complement components. In this study we show that the causative agent of Lyme disease, Borrelia burgdorferi, expresses a surface-protein termed BBK32 that targets and inhibits the first component of complement, designated C1. Upon binding to human C1, BBK32 traps this initiating protease complex of the classical pathway of complement in an inactive state, and prevents the downstream proteolytic events of the pathway. Our study defines a new mechanism by which microbes are able to escape the human innate immune system and identifies complement protease C1r as a previously unknown target of bacterial anti-complement molecules. Thus, discovery of the complement inhibitory activity of the borrelial protein BBK32 significantly advances our understanding of how disease-causing bacteria survive in immune competent hosts.
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Wagemakers A, Oei A, Fikrig MM, Miellet WR, Hovius JW. The relapsing fever spirochete Borrelia miyamotoi is cultivable in a modified Kelly-Pettenkofer medium, and is resistant to human complement. Parasit Vectors 2014; 7:418. [PMID: 25189195 PMCID: PMC4261524 DOI: 10.1186/1756-3305-7-418] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Accepted: 08/29/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Borrelia miyamotoi is a relapsing fever spirochete found in Ixodes ticks in North America, Europe, and Asia, and has recently been found to be invasive in humans. Cultivation of this spirochete has not yet been described, but is important for patient diagnostics and scientific purposes. Host specificity of Borrelia species is dependent on resistance to host complement (serum resistance), and since B. miyamotoi has been identified as a human pathogen we were interested whether B. miyamotoi is resistant to human complement. METHODS We inoculated B. miyamotoi strains LB-2001 and HT31 in modified-Kelly-Pettenkofer medium with 10% fetal calf serum (MKP-F), and used standard non-laborious Borrelia culture methods to culture the spirochetes. Next, we assessed serum sensitivity by a direct killing assay and a growth inhibition assay. RESULTS We were able to passage B. miyamotoi over 10 times using a standard culture method in MKP-F medium, and found B. miyamotoi to be resistant to human complement. In contrast to B. miyamotoi, Borrelia anserina--a relapsing fever spirochete unrelated to human infection--was serum sensitive. CONCLUSIONS Using a variation on MKP medium we were able to culture B. miyamotoi, opening the door to in vitro research into this spirochete. In addition, we describe that B. miyamotoi is resistant to human complement, which might play an important role in pathogenesis. We have also found B. anserina to be sensitive to human complement, which might explain why it is not related to human infection. Summarizing, we describe a novel culture method for B. miyamotoi and show it is resistant to human complement.
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Affiliation(s)
| | | | | | | | - Joppe W Hovius
- Center for Experimental and Molecular Medicine, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
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12
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The Borrelia hermsii factor H binding protein FhbA is not required for infectivity in mice or for resistance to human complement in vitro. Infect Immun 2014; 82:3324-32. [PMID: 24866803 DOI: 10.1128/iai.01892-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The primary causative agent of tick-borne relapsing fever in North America is Borrelia hermsii. It has been hypothesized that B. hermsii evades complement-mediated destruction by binding factor H (FH), a host-derived negative regulator of complement. In vitro, B. hermsii produces a single FH binding protein designated FhbA (FH binding protein A). The properties and ligand binding activity of FhbA suggest that it plays multiple roles in pathogenesis. It binds plasminogen and has been identified as a significant target of a B1b B cell-mediated IgM response in mice. FhbA has also been explored as a potential diagnostic antigen for B. hermsii infection in humans. The ability to test the hypothesis that FhbA is a critical virulence factor in vivo has been hampered by the lack of well-developed systems for the genetic manipulation of the relapsing fever spirochetes. In this report, we have successfully generated a B. hermsii fhbA deletion mutant (the B. hermsii YORΔfhbA strain) through allelic exchange mutagenesis. Deletion of fhbA abolished FH binding by the YORΔfhbA strain and eliminated cleavage of C3b on the cell surface. However, the YORΔfhbA strain remained infectious in mice and retained resistance to killing in vitro by human complement. Collectively, these results indicate that B. hermsii employs an FhbA/FH-independent mechanism of complement evasion that allows for resistance to killing by human complement and persistence in mice.
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13
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Aslam B, Hussain I, Mahmood MS, Khan A. Preparation and evaluation of Montanide ISA 206 adjuvanted bacterin of Borrelia anserina in laying chickens. J APPL POULTRY RES 2013. [DOI: 10.3382/japr.2012-00571] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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14
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Kišová-Vargová L, Cerňanská D, Bhide M. Comparative study of binding of ovine complement factor H with different Borrelia genospecies. Folia Microbiol (Praha) 2012; 57:123-8. [PMID: 22367885 DOI: 10.1007/s12223-012-0104-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Accepted: 09/06/2011] [Indexed: 11/28/2022]
Abstract
This study presents the binding of ovine factor H (fH) by various serotypes of Borrelia and simultaneously correlates their complement resistance to sheep serum. Affinity ligand binding assay was employed to study the binding of borrelial proteins to ovine recombinant fH and its truncated forms (short consensus repeat, SCR 7 and SCRs 19-20). From a repertoire of 17 borrelial strains, only two strains showed affinity to sheep fH. A ~28-kDa protein of Borrelia burgdorferi sensu stricto (B. burgdorferi s.s., strain SKT-2) bound full-length fH as well as SCRs 19-20. This fH-binding protein was further identified as complement regulator-acquiring surface protein of B. burgdorferi (BbCRASP-1) by MALDI-TOF analysis. Surprisingly, a ~26-kDa protein of Borrelia bissettii (DN127) showed affinity to full-length fH but not to SCR 7 and SCRs19-20. In complement sensitivity assay, both strains-SKT-2 and DN127-were resistant to normal sheep serum. Significant complement resistance of two Borrelia garinii strains (G117 and T25) was also observed; however, none of those strains was able to bind sheep fH. Our study underscores the need of further exploration of fH-mediated evasion of complement system by Borrelia in domestic animals.
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Affiliation(s)
- Lucia Kišová-Vargová
- Laboratory of Biomedical Microbiology and Immunology, University of Veterinary Medicine and Pharmacy, Komenského 73, 04181, Košice, Slovakia
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15
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Ferreira VP, Pangburn MK, Cortés C. Complement control protein factor H: the good, the bad, and the inadequate. Mol Immunol 2010; 47:2187-97. [PMID: 20580090 DOI: 10.1016/j.molimm.2010.05.007] [Citation(s) in RCA: 292] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The complement system is an essential component of the innate immune system that participates in elimination of pathogens and altered host cells and comprises an essential link between the innate and adaptive immune system. Soluble and membrane-bound complement regulators protect cells and tissues from unintended complement-mediated injury. Complement factor H is a soluble complement regulator essential for controlling the alternative pathway in blood and on cell surfaces. Normal recognition of self-cell markers (i.e. polyanions) and C3b/C3d fragments is necessary for factor H function. Inadequate recognition of host cell surfaces by factor H due to mutations and polymorphisms have been associated with complement-mediated tissue damage and disease. On the other hand, unwanted recognition of pathogens and altered self-cells (i.e. cancer) by factor H is used as an immune evasion strategy. This review will focus on the current knowledge related to these versatile recognition properties of factor H.
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Affiliation(s)
- Viviana P Ferreira
- Department of Medical Microbiology and Immunology, College of Medicine, University of Toledo, Toledo, OH 43614, United States.
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16
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Grosskinsky S, Schott M, Brenner C, Cutler SJ, Simon MM, Wallich R. Human complement regulators C4b-binding protein and C1 esterase inhibitor interact with a novel outer surface protein of Borrelia recurrentis. PLoS Negl Trop Dis 2010; 4:e698. [PMID: 20532227 PMCID: PMC2879370 DOI: 10.1371/journal.pntd.0000698] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Accepted: 04/06/2010] [Indexed: 11/23/2022] Open
Abstract
The spirochete Borrelia recurrentis is the causal agent of louse-borne relapsing fever and is transmitted to humans by the infected body louse Pediculus humanus. We have recently demonstrated that the B. recurrentis surface receptor, HcpA, specifically binds factor H, the regulator of the alternative pathway of complement activation, thereby inhibiting complement mediated bacteriolysis. Here, we show that B. recurrentis spirochetes express another potential outer membrane lipoprotein, termed CihC, and acquire C4b-binding protein (C4bp) and human C1 esterase inhibitor (C1-Inh), the major inhibitors of the classical and lectin pathway of complement activation. A highly homologous receptor for C4bp was also found in the African tick-borne relapsing fever spirochete B. duttonii. Upon its binding to B. recurrentis or recombinant CihC, C4bp retains its functional potential, i.e. facilitating the factor I-mediated degradation of C4b. The additional finding that ectopic expression of CihC in serum sensitive B. burgdorferi significantly increased spirochetal resistance against human complement suggests this receptor to substantially contribute, together with other known strategies, to immune evasion of B. recurrentis. Borrelia recurrentis, the causal agent of louse-borne relapsing fever is transmitted to humans via infected body lice. Infection with B. recurrentis has been achieved only in humans and is accompanied by a systemic inflammatory disease, multiple relapses of fever and massive spirochetemia. A key virulence factor of B. recurrentis is their potential to undergo antigenic variation. However, for survival in the blood during the early phase of infection and for persistence in human tissues, spirochetes must be endowed with robust tools to escape innate immunity. We have recently shown that B. recurrentis acquires the serum-derived regulator factor H, thereby blocking the alternative complement pathway. Here, we show that B. recurrentis expresses in addition a novel outer surface lipoprotein that selectively binds serum-derived C4b-binding protein and C1 esterase inhibitor, two endogenous regulators of the classical and lectin pathway of complement activation. The combined data underscore the versatility of B. recurrentis to effectively evade innate and adaptive immunity, including serum resistance. Thus, the present study elucidates a new mechanism of B. recurrentis important for its evasion from complement attack and will be helpful for the development of new drugs against this fatal infection.
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Affiliation(s)
- Sonja Grosskinsky
- Infectious Immunology Group, Institute for Immunology, University of Heidelberg, Heidelberg, Germany
| | - Melanie Schott
- Infectious Immunology Group, Institute for Immunology, University of Heidelberg, Heidelberg, Germany
| | - Christiane Brenner
- Infectious Immunology Group, Institute for Immunology, University of Heidelberg, Heidelberg, Germany
| | - Sally J. Cutler
- School of Health and Bioscience, University of East London, Stratford, London, United Kingdom
| | - Markus M. Simon
- Infectious Immunology Group, Institute for Immunology, University of Heidelberg, Heidelberg, Germany
| | - Reinhard Wallich
- Infectious Immunology Group, Institute for Immunology, University of Heidelberg, Heidelberg, Germany
- * E-mail:
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17
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Molecular characterization of the interaction of Borrelia parkeri and Borrelia turicatae with human complement regulators. Infect Immun 2010; 78:2199-208. [PMID: 20231403 DOI: 10.1128/iai.00089-10] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
In North America, tick-borne relapsing fever is caused by the species Borrelia hermsii, B. parkeri, and B. turicatae, which are transmitted to humans through the bite of the respective infected tick vectors. Here we describe the identification and functional characterization of a surface lipoprotein of B. parkeri, designated BpcA, that binds the human complement regulators factor H and factor H-related protein 1 and, simultaneously, the host protease plasminogen. In contrast, the homologous B. turicatae protein failed to bind human factor H and factor H-related protein 1 but retained its plasminogen binding capacity. Factor H bound to BpcA maintains its regulatory capacity to control C3b deposition and C3 convertase activity. Ectopic expression of BpcA in a serum-sensitive B. burgdorferi strain protects transformed cells from complement-mediated killing. Furthermore, bound plasminogen/plasmin endows B. parkeri and B. turicatae with the potential to degrade extracellular matrix components. These findings expand our understanding of the putative recent evolutionary separation of Borrelia parkeri and Borrelia turicatae, provide evidence that B. parkeri differs from B. turicatae in its ability to resist complement attack, and may help in understanding the pathological processes underlying tick-borne relapsing fever.
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18
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Comparative analysis of the properties and ligand binding characteristics of CspZ, a factor H binding protein, derived from Borrelia burgdorferi isolates of human origin. Infect Immun 2009; 77:4396-405. [PMID: 19620346 DOI: 10.1128/iai.00393-09] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Borrelia burgdorferi CspZ (BBH06/BbCRASP-2) binds the complement regulatory protein factor H (FH) and additional unidentified serum proteins. The goals of this study were to assess the ligand binding capability of CspZ orthologs derived from an extensive panel of human Lyme disease isolates and to further define the molecular basis of the interaction between FH and CspZ. While most B. burgdorferi CspZ orthologs analyzed bound FH, specific, naturally occurring polymorphisms, most of which clustered in a specific loop domain of CspZ, prevented FH binding in some orthologs. Sequence analyses also revealed the existence of CspZ phyletic groups that correlate with FH binding and with the relationships inferred from ribosomal spacer types (RSTs). CspZ type 1 (RST1) and type 3 (RST3) strains bind FH, while CspZ type 2 (RST2) strains do not. Antibody responses to CspZ were also assessed. Anti-CspZ antibodies were detected in mice by week 2 of infection, indicating that there was expression during early-stage infection. Analyses of sera collected from infected mice suggested that CspZ production continued over the course of long-term infection as the antibody titer increased over time. While antibody to CspZ was detected in several human Lyme disease serum samples, the response was not universal, and the titers were generally low. Vaccination studies with mice demonstrated that while CspZ is immunogenic, it does not elicit an antibody that is protective or that inhibits dissemination. The data presented here provide significant new insight into the interaction between CspZ and FH and suggest that there is a correlation between CspZ production and dissemination. However, in spite of its possible contributory role in pathogenesis, the immunological analyses indicated that CspZ is likely to have limited potential as a diagnostic marker and vaccine candidate for Lyme disease.
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Bhide MR, Escudero R, Camafeita E, Gil H, Jado I, Anda P. Complement factor H binding by different Lyme disease and relapsing fever Borrelia in animals and human. BMC Res Notes 2009; 2:134. [PMID: 19604355 PMCID: PMC2717971 DOI: 10.1186/1756-0500-2-134] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2009] [Accepted: 07/15/2009] [Indexed: 11/19/2022] Open
Abstract
Background Borreliae employ multiple immune evasive strategies such as binding to complement regulatory proteins [factor H (fH) and factor H like-1 (FHL1)], differential regulation of surface membrane proteins, antigenic variation, and binding of plasminogen/plasmin and matrix metalloproteinases. As a complement regulatory subunit, fH serves as a cofactor for the factor I-mediated cleavage of C3b. fH binding by Borrelia has been correlated with pathogenesis as well as with host diversity. Here we show the differential binding of borrelial proteins to fH from human and animal sera. Findings Affinity ligand binding experiments, 2-D electrophoresis, and protein identification and peptide de novo sequencing based on mass spectrometry, revealed novel fH putative binding proteins of Lyme- and relapsing fever Borrelia. An OspA serotype-associated differential human and animal fH binding by B. garinii was also observed, which could be related with the ability of some strains from serotypes 4 and 7 to invade non-nervous system tissues. Also, the variable affinity of binding proteins expressed by different Borrelia to animal fH correlated with their host selectivity. Conclusion The novel animal and human putative fH binding proteins (FHBPs) in this study underscore the importance of evasion of complement in the pathogenesis of Borrelia infections.
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Affiliation(s)
- Mangesh R Bhide
- Laboratorio de Espiroquetas y Patógenos Especiales, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
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20
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Woodman ME, Cooley AE, Avdiushko R, Bowman A, Botto M, Wooten RM, van Rooijen N, Cohen DA, Stevenson B. Roles for phagocytic cells and complement in controlling relapsing fever infection. J Leukoc Biol 2009; 86:727-36. [PMID: 19458267 DOI: 10.1189/jlb.0309169] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Relapsing fever spirochetes, such as Borrelia hermsii, proliferate to high levels in their hosts' bloodstream until production of IgM against borrelial surface proteins promotes bacterial clearance. The mechanisms by which B. hermsii survives in host blood, as well as the immune mediators that control this infection, remain largely unknown. It has been hypothesized that B. hermsii is naturally resistant to killing by the alternative pathway of complement activation as a result of its ability to bind factor H, a host complement regulator. However, we found that Cfh(-/-) mice were infected to levels identical to those seen in wild-type mice. Moreover, only a small minority of B. hermsii in the blood of wild-type mice had detectable levels of factor H adhered to their outer surfaces. In vitro, complement was found to play a statistically significant role in antibody-mediated inactivation of B. hermsii, although in vivo studies indicated that complement is not essential for host control of B. hermsii. Depletion of mphi and DC from mice had significant impacts on B. hermsii infection, and depleted mice were unable to control bloodstream infections, leading to death. Infection studies using muMT indicated a significant antibody-independent role for mphi and/or DC in host control of relapsing fever infection. Together, these findings indicate mphi and/or DC play a critical role in the production of B. hermsii-specific IgM and for antibody-independent control of spirochete levels.
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Affiliation(s)
- Michael E Woodman
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY 40536-0298, USA
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21
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Grosskinsky S, Schott M, Brenner C, Cutler SJ, Kraiczy P, Zipfel PF, Simon MM, Wallich R. Borrelia recurrentis employs a novel multifunctional surface protein with anti-complement, anti-opsonic and invasive potential to escape innate immunity. PLoS One 2009; 4:e4858. [PMID: 19308255 PMCID: PMC2654920 DOI: 10.1371/journal.pone.0004858] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Accepted: 02/13/2009] [Indexed: 12/28/2022] Open
Abstract
Borrelia recurrentis, the etiologic agent of louse-borne relapsing fever in humans, has evolved strategies, including antigenic variation, to evade immune defence, thereby causing severe diseases with high mortality rates. Here we identify for the first time a multifunctional surface lipoprotein of B. recurrentis, termed HcpA, and demonstrate that it binds human complement regulators, Factor H, CFHR-1, and simultaneously, the host protease plasminogen. Cell surface bound factor H was found to retain its activity and to confer resistance to complement attack. Moreover, ectopic expression of HcpA in a B. burgdorferi B313 strain, deficient in Factor H binding proteins, protected the transformed spirochetes from complement-mediated killing. Furthermore, HcpA-bound plasminogen/plasmin endows B. recurrentis with the potential to resist opsonization and to degrade extracellular matrix components. Together, the present study underscores the high virulence potential of B. recurrentis. The elucidation of the molecular basis underlying the versatile strategies of B. recurrentis to escape innate immunity and to persist in human tissues, including the brain, may help to understand the pathological processes underlying louse-borne relapsing fever.
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Affiliation(s)
- Sonja Grosskinsky
- Infectious Immunology, Institute for Immunology, University of Heidelberg, Heidelberg, Germany
| | - Melanie Schott
- Infectious Immunology, Institute for Immunology, University of Heidelberg, Heidelberg, Germany
| | - Christiane Brenner
- Infectious Immunology, Institute for Immunology, University of Heidelberg, Heidelberg, Germany
| | - Sally J. Cutler
- School of Health and Bioscience, University of East London, Stratford, London, United Kingdom
| | - Peter Kraiczy
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Frankfurt/Main, Germany
| | - Peter F. Zipfel
- Department of Infection Biology, Leibniz-Institute for Natural Products Research, Jena, Germany
| | - Markus M. Simon
- Metschnikoff Laboratory, Max-Planck-Institute for Immunobiology, Freiburg, Germany
| | - Reinhard Wallich
- Infectious Immunology, Institute for Immunology, University of Heidelberg, Heidelberg, Germany
- * E-mail:
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22
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Analysis of a unique interaction between the complement regulatory protein factor H and the periodontal pathogen Treponema denticola. Infect Immun 2009; 77:1417-25. [PMID: 19204088 DOI: 10.1128/iai.01544-08] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Treponema denticola, a spirochete associated with periodontitis, is abundant at the leading edge of subgingival plaque, where it interacts with gingival epithelia. T. denticola produces a number of virulence factors, including dentilisin, a protease which is cytopathic to host cells, and FhbB, a unique T. denticola lipoprotein that binds complement regulatory proteins. Earlier analyses suggested that FhbB specifically bound to factor H (FH)-like protein 1 (FHL-1). However, by using dentilisin-deficient mutants of T. denticola, we found that T. denticola preferentially binds FH and not FHL-1, and that FH is then cleaved by dentilisin to yield an FH subfragment of approximately 50 kDa. FH bound to dentilisin-deficient mutants but was not cleaved and retained its ability to serve as a cofactor for factor I in the cleavage of C3b. To assess the molecular basis of the interaction of FhbB with FH, mutational analyses were conducted. Replacement of specific residues in widely separated domains of FhbB and disruption of a central alpha helix with coiled-coil formation probability attenuated or eliminated FH binding. The data presented here are the first to demonstrate the retention at the cell surface of a proteolytic cleavage product of FH. The precise role of this FH fragment in the host-pathogen interaction remains to be determined.
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23
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Siegel C, Schreiber J, Haupt K, Skerka C, Brade V, Simon MM, Stevenson B, Wallich R, Zipfel PF, Kraiczy P. Deciphering the ligand-binding sites in the Borrelia burgdorferi complement regulator-acquiring surface protein 2 required for interactions with the human immune regulators factor H and factor H-like protein 1. J Biol Chem 2008; 283:34855-63. [PMID: 18824548 PMCID: PMC2596382 DOI: 10.1074/jbc.m805844200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Revised: 09/12/2008] [Indexed: 11/06/2022] Open
Abstract
Borrelia burgdorferi, the etiologic agent of Lyme disease, employs sophisticated means to evade killing by its mammalian hosts. One important immune escape mechanism is the inhibition of complement activation mediated by interactions of the host-derived immune regulators factor H (CFH) and factor H-like protein 1 (CFHL1) with borrelial complement regulator-acquiring surface proteins (BbCRASPs). BbCRASP-2 is a distinctive CFH- and CFHL1-binding protein that is produced by serum-resistant B. burgdorferi strains. Here we show that binding of CFH by BbCRASP-2 is due to electrostatic as well as hydrophobic forces. In addition, 14 individual amino acid residues of BbCRASP-2 were identified as being involved in CFH and CFHL1 binding. Alanine substitutions of most of those residues significantly inhibited binding of CFH and/or CFHL1 by recombinant BbCRASP-2 proteins. To conclusively define the effects of BbCRASP-2 residue substitutions on serum sensitivity in the bacterial context, a serum-sensitive Borrelia garinii strain was transformed with plasmids that directed production of either wild-type or mutated BbCRASP-2 proteins. Critical amino acid residues within BbCRASP-2 were identified, with bacteria producing distinct mutant proteins being unable to bind either CFH or CFHL1, showing high levels of complement components C3, C6, and C5b-9 deposited on their surfaces and being highly sensitive to killing by normal serum. Collectively, we mapped a structurally sensitive CFH/CFHL1 binding site within borrelial BbCRASP-2 and identified single amino acid residues potentially involved in the interaction with both complement regulators.
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Affiliation(s)
- Corinna Siegel
- Institute of Medical Microbiology and
Infection Control, University Hospital of Frankfurt, Paul-Ehrlich-Strasse 40,
60596 Frankfurt, Germany, the Department of
Infection Biology, Leibniz-Institute for Natural Products Research and
Infection Biology, 07745 Jena, Germany, the
Metschnikoff Laboratory, Max-Planck-Institute
for Immunobiology, 79108 Freiburg, Germany, the
Department of Microbiology, Immunology and
Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536, the
Institute of Immunology, University of Heidelberg,
69120 Heidelberg, Germany, and the
Friedrich Schiller University, 07743
Jena, Germany
| | - Johanna Schreiber
- Institute of Medical Microbiology and
Infection Control, University Hospital of Frankfurt, Paul-Ehrlich-Strasse 40,
60596 Frankfurt, Germany, the Department of
Infection Biology, Leibniz-Institute for Natural Products Research and
Infection Biology, 07745 Jena, Germany, the
Metschnikoff Laboratory, Max-Planck-Institute
for Immunobiology, 79108 Freiburg, Germany, the
Department of Microbiology, Immunology and
Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536, the
Institute of Immunology, University of Heidelberg,
69120 Heidelberg, Germany, and the
Friedrich Schiller University, 07743
Jena, Germany
| | - Katrin Haupt
- Institute of Medical Microbiology and
Infection Control, University Hospital of Frankfurt, Paul-Ehrlich-Strasse 40,
60596 Frankfurt, Germany, the Department of
Infection Biology, Leibniz-Institute for Natural Products Research and
Infection Biology, 07745 Jena, Germany, the
Metschnikoff Laboratory, Max-Planck-Institute
for Immunobiology, 79108 Freiburg, Germany, the
Department of Microbiology, Immunology and
Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536, the
Institute of Immunology, University of Heidelberg,
69120 Heidelberg, Germany, and the
Friedrich Schiller University, 07743
Jena, Germany
| | - Christine Skerka
- Institute of Medical Microbiology and
Infection Control, University Hospital of Frankfurt, Paul-Ehrlich-Strasse 40,
60596 Frankfurt, Germany, the Department of
Infection Biology, Leibniz-Institute for Natural Products Research and
Infection Biology, 07745 Jena, Germany, the
Metschnikoff Laboratory, Max-Planck-Institute
for Immunobiology, 79108 Freiburg, Germany, the
Department of Microbiology, Immunology and
Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536, the
Institute of Immunology, University of Heidelberg,
69120 Heidelberg, Germany, and the
Friedrich Schiller University, 07743
Jena, Germany
| | - Volker Brade
- Institute of Medical Microbiology and
Infection Control, University Hospital of Frankfurt, Paul-Ehrlich-Strasse 40,
60596 Frankfurt, Germany, the Department of
Infection Biology, Leibniz-Institute for Natural Products Research and
Infection Biology, 07745 Jena, Germany, the
Metschnikoff Laboratory, Max-Planck-Institute
for Immunobiology, 79108 Freiburg, Germany, the
Department of Microbiology, Immunology and
Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536, the
Institute of Immunology, University of Heidelberg,
69120 Heidelberg, Germany, and the
Friedrich Schiller University, 07743
Jena, Germany
| | - Markus M. Simon
- Institute of Medical Microbiology and
Infection Control, University Hospital of Frankfurt, Paul-Ehrlich-Strasse 40,
60596 Frankfurt, Germany, the Department of
Infection Biology, Leibniz-Institute for Natural Products Research and
Infection Biology, 07745 Jena, Germany, the
Metschnikoff Laboratory, Max-Planck-Institute
for Immunobiology, 79108 Freiburg, Germany, the
Department of Microbiology, Immunology and
Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536, the
Institute of Immunology, University of Heidelberg,
69120 Heidelberg, Germany, and the
Friedrich Schiller University, 07743
Jena, Germany
| | - Brian Stevenson
- Institute of Medical Microbiology and
Infection Control, University Hospital of Frankfurt, Paul-Ehrlich-Strasse 40,
60596 Frankfurt, Germany, the Department of
Infection Biology, Leibniz-Institute for Natural Products Research and
Infection Biology, 07745 Jena, Germany, the
Metschnikoff Laboratory, Max-Planck-Institute
for Immunobiology, 79108 Freiburg, Germany, the
Department of Microbiology, Immunology and
Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536, the
Institute of Immunology, University of Heidelberg,
69120 Heidelberg, Germany, and the
Friedrich Schiller University, 07743
Jena, Germany
| | - Reinhard Wallich
- Institute of Medical Microbiology and
Infection Control, University Hospital of Frankfurt, Paul-Ehrlich-Strasse 40,
60596 Frankfurt, Germany, the Department of
Infection Biology, Leibniz-Institute for Natural Products Research and
Infection Biology, 07745 Jena, Germany, the
Metschnikoff Laboratory, Max-Planck-Institute
for Immunobiology, 79108 Freiburg, Germany, the
Department of Microbiology, Immunology and
Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536, the
Institute of Immunology, University of Heidelberg,
69120 Heidelberg, Germany, and the
Friedrich Schiller University, 07743
Jena, Germany
| | - Peter F. Zipfel
- Institute of Medical Microbiology and
Infection Control, University Hospital of Frankfurt, Paul-Ehrlich-Strasse 40,
60596 Frankfurt, Germany, the Department of
Infection Biology, Leibniz-Institute for Natural Products Research and
Infection Biology, 07745 Jena, Germany, the
Metschnikoff Laboratory, Max-Planck-Institute
for Immunobiology, 79108 Freiburg, Germany, the
Department of Microbiology, Immunology and
Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536, the
Institute of Immunology, University of Heidelberg,
69120 Heidelberg, Germany, and the
Friedrich Schiller University, 07743
Jena, Germany
| | - Peter Kraiczy
- Institute of Medical Microbiology and
Infection Control, University Hospital of Frankfurt, Paul-Ehrlich-Strasse 40,
60596 Frankfurt, Germany, the Department of
Infection Biology, Leibniz-Institute for Natural Products Research and
Infection Biology, 07745 Jena, Germany, the
Metschnikoff Laboratory, Max-Planck-Institute
for Immunobiology, 79108 Freiburg, Germany, the
Department of Microbiology, Immunology and
Molecular Genetics, University of Kentucky, Lexington, Kentucky 40536, the
Institute of Immunology, University of Heidelberg,
69120 Heidelberg, Germany, and the
Friedrich Schiller University, 07743
Jena, Germany
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Rossmann E, Kraiczy P, Herzberger P, Skerka C, Kirschfink M, Simon MM, Zipfel PF, Wallich R. BhCRASP-1 of the relapsing fever spirochete Borrelia hermsii is a factor H- and plasminogen-binding protein. Int J Med Microbiol 2008. [DOI: 10.1016/j.ijmm.2008.02.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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25
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LaRocca TJ, Katona LI, Thanassi DG, Benach JL. Bactericidal action of a complement-independent antibody against relapsing fever Borrelia resides in its variable region. THE JOURNAL OF IMMUNOLOGY 2008; 180:6222-8. [PMID: 18424744 DOI: 10.4049/jimmunol.180.9.6222] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A single chain variable fragment (scFv) of CB515, a complement-independent bactericidal monoclonal IgM against a relapsing fever Borrelia, was constructed to investigate the region wherein the unique bactericidal function resides. Monomeric CB515 scFv (26 kDa) was capable of binding its Ag on whole organisms and by immunoblot. This binding was shown to be species and serotype-specific to the 19 kDa variable small protein, recognized by its parent monoclonal IgM. A dose-dependent bactericidal effect of the CB515 scFv was detected by direct enumeration of spirochetes. Spirochetes incubated with the CB515 scFv before inoculation into mice grew into escape mutants, whereas spirochetes incubated with an irrelevant scFv developed as the original infecting serotype. This bactericidal effect, as seen at the ultrastructural level, was due to disruption of the outer membrane and to severe membrane blebbing eventually progressing to lysis. These results indicate that the variable region of CB515 is responsible for this bactericidal activity and that the constant region of the Ab is dispensable.
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Affiliation(s)
- Timothy J LaRocca
- Center for Infectious Diseases, Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794, USA
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26
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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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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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Herzberger P, Siegel C, Skerka C, Fingerle V, Schulte-Spechtel U, van Dam A, Wilske B, Brade V, Zipfel PF, Wallich R, Kraiczy P. Human pathogenic Borrelia spielmanii sp. nov. resists complement-mediated killing by direct binding of immune regulators factor H and factor H-like protein 1. Infect Immun 2007; 75:4817-25. [PMID: 17635869 PMCID: PMC2044541 DOI: 10.1128/iai.00532-07] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Borrelia spielmanii sp. nov. has recently been shown to be a novel human pathogenic genospecies that causes Lyme disease in Europe. In order to elucidate the immune evasion mechanisms of B. spielmanii, we compared the abilities of isolates obtained from Lyme disease patients and tick isolate PC-Eq17 to escape from complement-mediated bacteriolysis. Using a growth inhibition assay, we show that four B. spielmanii isolates, including PC-Eq17, are serum resistant, whereas a single isolate, PMew, was more sensitive to complement-mediated lysis. All isolates activated complement in vitro, as demonstrated by covalent attachment of C3 fragments; however, deposition of the later activation products C6 and C5b-9 was restricted to the moderately serum-resistant isolate PMew and the serum-sensitive B. garinii isolate G1. Furthermore, serum adsorption experiments revealed that all B. spielmanii isolates acquired the host alternative pathway regulators factor H and factor H-like protein (FHL-1) from human serum. Both complement regulators retained their factor I-mediated C3b inactivation activities when bound to spirochetes. In addition, two distinct factor H and FHL-1 binding proteins, BsCRASP-1 and BsCRASP-2, were identified, which we estimated to be approximately 23 to 25 kDa in mass. A further factor H binding protein, BsCRASP-3, was found exclusively in the tick isolate, PC-Eq17. This is the first report describing an immune evasion mechanism utilized by B. spielmanii sp. nov., and it demonstrates the capture of human immune regulators to resist complement-mediated killing.
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Affiliation(s)
- Pia Herzberger
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Paul-Ehrlich-Str. 40, D-60596 Frankfurt, Germany
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Rossmann E, Kraiczy P, Herzberger P, Skerka C, Kirschfink M, Simon MM, Zipfel PF, Wallich R. Dual binding specificity of a Borrelia hermsii-associated complement regulator-acquiring surface protein for factor H and plasminogen discloses a putative virulence factor of relapsing fever spirochetes. THE JOURNAL OF IMMUNOLOGY 2007; 178:7292-301. [PMID: 17513779 DOI: 10.4049/jimmunol.178.11.7292] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Tick-borne relapsing fever in North America is primarily caused by the spirochete Borrelia hermsii. The pathogen employs multiple strategies, including the acquisition of complement regulators and antigenic variation, to escape innate and humoral immunity. In this study we identified in B. hermsii a novel member of the complement regulator-acquiring surface protein (CRASP) family, designated BhCRASP-1, that binds the complement regulators factor H (FH) and FH-related protein 1 (FHR-1) but not FH-like protein 1 (FHL-1). BhCRASP-1 specifically interacts with the short consensus repeat 20 of FH, thereby maintaining FH-associated cofactor activity for factor I-mediated C3b inactivation. Furthermore, ectopic expression of BhCRASP- 1 converted the serum-sensitive Borrelia burgdorferi B313 strain into an intermediate complement-resistant strain. Finally, we report for the first time that BhCRASP-1 binds plasminogen/plasmin in addition to FH via, however, distinct nonoverlapping domains. The fact that surface-bound plasmin retains its proteolytic activity suggest that the dual binding specificity of BhCRASP-1 for FH and plasminogen/plasmin contributes to both the dissemination/invasion of B. hermsii and its resistance to innate immunity.
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Affiliation(s)
- Evelyn Rossmann
- Infectious Immunology Group, Institute for Immunology, University of Heidelberg, Heidelberg, Germany
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30
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Macor P, Tedesco F. Complement as effector system in cancer immunotherapy. Immunol Lett 2007; 111:6-13. [PMID: 17572509 DOI: 10.1016/j.imlet.2007.04.014] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2007] [Accepted: 04/30/2007] [Indexed: 11/28/2022]
Abstract
The contribution of the complement system to the control of tumour growth has been neglected for a long time as the major emphasis has been put mainly on cell-mediated immune response against cancer. With the introduction of monoclonal antibodies in cancer immunotherapy complement has come into play with a great potential as effector system. Complement has a number of advantages over other effector systems in that it is made of molecules that can easily penetrate the tumour tissue and a large majority, if not all, of the components of this system can be supplied locally by many cells at tissue site. Further advances are being made to increase the anti-tumour efficiency of the complements system using C-fixing antibodies that are modified in the Fc portion to be more active in complement activation. Another strategy currently investigated is essentially based on the use of a combination of two antibodies directed against different molecules or different epitopes of the same molecule expressed on the cell surface in order to increase the number of the binding sites for the antibodies on the tumor cells and the chance for them to activate complement more efficiently. One of the problems to solve in exploiting complement as an effector system in cancer immunotherapy is to neutralize the inhibitory effect of complement regulatory proteins which are often over-expressed on tumour cells and represent a mechanism of evasion of these cells from complement attack. This situation can be overcome using neutralizing antibodies to target onto tumour cells together with the specific antibodies directed against tumor specific antigens. This is an area of active investigation and the initial data that start to be available from animal models seem to be promising.
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Affiliation(s)
- Paolo Macor
- Department of Physiology and Pathology, University of Trieste, Via Fleming 22, Trieste 34127, Italy
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31
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Kraiczy P, Rossmann E, Brade V, Simon MM, Skerka C, Zipfel PF, Wallich R. Binding of human complement regulators FHL-1 and factor H to CRASP-1 orthologs of Borrelia burgdorferi. Wien Klin Wochenschr 2007; 118:669-76. [PMID: 17160605 DOI: 10.1007/s00508-006-0691-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The complement regulator-acquiring surface protein (CRASP)-1 is a member of the paralogous gene family gbb54 and the dominant FHL-1 and factor H binding protein of Borrelia burgdorferi sensu stricto (s.s.). It was shown recently that expression of BbCRASP-1 directly correlates with serum resistance of B. burgdorferi s.s. isolates. In the present study we have elucidated the putative potential of other members of the gbb54 paralogous family, including orthologs ZSA66, ZSA69, ZSA70, ZSA71, ZSA72 and ZSA73 of the European B. burgdorferi s.s. strain ZS7, to bind human FHL-1 and factor H. In spite of their overall similarity in protein sequence, between 47% and 67%, and the fact that the C-terminal region of ZSA69 shows 70% similarity with BbCRASP-1, none of the orthologous proteins was able to bind human FHL-1 and/or factor H. BbCRASP-1 is the only member of the paralogous gene family gbb54 that binds to human complement regulators, supporting the notion that BbCRASP-1 plays a critical role in evasion of complement by B. burgdorferi s.s. and thus may be helpful in the development of novel therapeutic strategies against Lyme borreliosis.
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Affiliation(s)
- Peter Kraiczy
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Frankfurt, Germany.
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32
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Hartmann K, Corvey C, Skerka C, Kirschfink M, Karas M, Brade V, Miller JC, Stevenson B, Wallich R, Zipfel PF, Kraiczy P. Functional characterization of BbCRASP-2, a distinct outer membrane protein of Borrelia burgdorferi that binds host complement regulators factor H and FHL-1. Mol Microbiol 2006; 61:1220-36. [PMID: 16925556 DOI: 10.1111/j.1365-2958.2006.05318.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Borrelia burgdorferi, the aetiological agent of Lyme disease, employs sophisticated means to survive in diverse mammalian hosts. Recent studies demonstrated that acquisition of complement regulators factor H and factor H-like protein-1 (FHL-1) allows spirochetes to resist complement-mediated killing. Serum-resistant B. burgdorferi express up to five distinct complement regulator-acquiring surface proteins (CRASPs) that bind factor H and/or FHL-1. In this study we have identified and characterized one of those B. burgdorferi proteins, named BbCRASP-2. BbCRASP-2 is distinct from the four previously identified factor H/FHL-1-binding CRASPs of B. burgdorferi strains. The single copy of the gene encoding BbCRASP-2, cspZ, is located on the linear plasmid lp28-3. BbCRASP-2 is highly divergent from the factor H/FHL-1-binding protein BbCRASP-1 and from members of the factor H-binding Erp (OspE/F-related) protein family. Peptide mapping analysis revealed that the factor H/FHL-1 binding site is discontinuous and it was found that C-terminal truncations abrogate factor H and FHL-1 binding. The predominant BbCRASP-2 binding site of both host complement regulators was mapped to the short consensus repeat 7 (SCR 7). Factor H and FHL-1 bound to BbCRASP-2 maintain cofactor activity for factor I-mediated C3b inactivation and accelerate the decay of the C3 convertase. Expression of BbCRASP-2 in serum-sensitive B. burgdorferi mutant B313 increased resistance to complement-mediated lysis. The characterization of BbCRASP-2 now provides a complete picture of the three diverse complement regulator-binding protein families of B. burgdorferi yielding new insights into the pathogenesis of Lyme disease.
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Affiliation(s)
- Kristina Hartmann
- Institute of Medical Microbiology, University Hospital of Frankfurt, Paul-Ehrlich-Str. 40, 60596 Frankfurt, Germany
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33
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McDowell JV, Frederick J, Stamm L, Marconi RT. Identification of the gene encoding the FhbB protein of Treponema denticola, a highly unique factor H-like protein 1 binding protein. Infect Immun 2006; 75:1050-4. [PMID: 17101650 PMCID: PMC1828522 DOI: 10.1128/iai.01458-06] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The gene encoding the Treponema denticola factor H-like protein 1 (FHL-1) binding protein, FhbB, was recovered and characterized. Sequence conservation, expression, and properties of FhbB were analyzed. The identification of FhbB represents an important step in understanding the contribution of FHL-1 binding in T. denticola pathogenesis and in development of periodontal disease.
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Affiliation(s)
- John V McDowell
- Department of Microbiology and Immunology, Medical College of Virginia at Virginia Commonwealth University, Richmond, Virginia 23298-0678, USA
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34
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Hovis KM, Schriefer ME, Bahlani S, Marconi RT. Immunological and molecular analyses of the Borrelia hermsii factor H and factor H-like protein 1 binding protein, FhbA: demonstration of its utility as a diagnostic marker and epidemiological tool for tick-borne relapsing fever. Infect Immun 2006; 74:4519-29. [PMID: 16861638 PMCID: PMC1539583 DOI: 10.1128/iai.00377-06] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
It has been demonstrated that Borrelia hermsii, a causative agent of relapsing fever, produces a factor H (FH) and FH-like protein 1 (FHL-1) binding protein. The binding protein has been designated FhbA. To determine if FH/FHL-1 binding is widespread among B. hermsii isolates, a diverse panel of strains was tested for the FH/FHL-1 binding phenotype and FhbA production. Most isolates (23/24) produced FhbA and bound FH/FHL-1. Potential variation in FhbA among isolates was analyzed by DNA sequence analyses. Two genetically distinct FhbA types, designated fhbA1 and fhbA2, were delineated, and type-specific PCR primers were generated to allow for rapid differentiation. Pulsed-field gel electrophoresis and hybridization analyses demonstrated that all isolates that possess the gene carry it on a 200-kb linear plasmid (lp200), whereas isolates that lack the gene lack lp200 and instead carry an lp170. To determine if FhbA is antigenic during infection and to assess the specificity of the response, recombinant FhbA1 (rFhbA1) and rFhbA2 were screened with serum from infected mice and humans. FhbA was found to be expressed and antigenic and to elicit a potentially type-specific FhbA response. To localize the epitopes of FhbA1 and FhbA2, truncations were generated and screened with infection serum. The epitopes were determined to be conformationally defined. Collectively, these analyses indicate that FH/FHL-1 binding is a widespread virulence mechanism for B. hermsii and provide insight into the genetic and antigenic structure of FhbA. The data also have potential implications for understanding the epidemiology of relapsing fever in North America and can be applied to the future development of species-specific diagnostic tools.
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Affiliation(s)
- Kelley M Hovis
- Department of Microbiology and Immunology, Medical College of Virginia at Virginia Commonwealth University, 1112 E. Clay St., McGuire Hall, Richmond, Virginia 23298-0678, USA
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35
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Meri T, Cutler SJ, Blom AM, Meri S, Jokiranta TS. Relapsing fever spirochetes Borrelia recurrentis and B. duttonii acquire complement regulators C4b-binding protein and factor H. Infect Immun 2006; 74:4157-63. [PMID: 16790790 PMCID: PMC1489703 DOI: 10.1128/iai.00007-06] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Relapsing fever is a rapidly progressive and severe septic disease caused by certain Borrelia spirochetes. The disease is divided into two forms, i.e., epidemic relapsing fever, caused by Borrelia recurrentis and transmitted by lice, and the endemic form, caused by several Borrelia species, such as B. duttonii, and transmitted by soft-bodied ticks. The spirochetes enter the bloodstream by the vector bite and live persistently in plasma even after the development of specific antibodies. This leads to fever relapses and high mortality and clearly indicates that the Borrelia organisms utilize effective immune evasion strategies. In this study, we show that the epidemic relapsing fever pathogen B. recurrentis and an endemic relapsing fever pathogen, B. duttonii, are serum resistant, i.e., resistant to complement in vitro. They acquire the host alternative complement pathway regulator factor H on their surfaces in a similar way to that of the less serum-resistant Lyme disease pathogen, B. burgdorferi sensu stricto. More importantly, the relapsing fever spirochetes specifically bind host C4b-binding protein, a major regulator of the antibody-mediated classical complement pathway. Both complement regulators retained their functional activities when bound to the surfaces of the spirochetes. In conclusion, this is the first report of complement evasion by Borrelia recurrentis and B. duttonii and the first report showing capture of C4b-binding protein by spirochetes.
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Affiliation(s)
- T Meri
- Haartman Institute, Department of Bacteriology and Immunology, P.O. Box 21, University of Helsinki, FIN-00014 Helsinki, Finland.
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36
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Hovis KM, Tran E, Sundy CM, Buckles E, McDowell JV, Marconi RT. Selective binding of Borrelia burgdorferi OspE paralogs to factor H and serum proteins from diverse animals: possible expansion of the role of OspE in Lyme disease pathogenesis. Infect Immun 2006; 74:1967-72. [PMID: 16495576 PMCID: PMC1418677 DOI: 10.1128/iai.74.3.1967-1972.2006] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The binding of Borrelia burgdorferi OspE, OspF, and family 163 (Elp) proteins to factor H/factor H-like protein 1 (FHL-1) and other serum proteins from different animals was assessed. OspE paralogs bound factor H and unidentified serum proteins from a subset of animals, while OspF and Elp proteins did not. These data advance our understanding of factor H binding, the host range of the Lyme spirochetes, and the expanding role of OspE in pathogenesis.
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Affiliation(s)
- Kelley M Hovis
- Department of Microbiology and Immunology, Medical College of Virginia at Virginia Commonwealth University, 1112 E. Clay St., Richmond, VA 23298-0678, USA
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37
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Hovis KM, Jones JP, Sadlon T, Raval G, Gordon DL, Marconi RT. Molecular analyses of the interaction of Borrelia hermsii FhbA with the complement regulatory proteins factor H and factor H-like protein 1. Infect Immun 2006; 74:2007-14. [PMID: 16552029 PMCID: PMC1418896 DOI: 10.1128/iai.74.4.2007-2014.2006] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Borrelia hermsii, the primary etiological agent of tick-borne relapsing fever in North America, binds the complement regulatory protein factor H (FH) as a means of evading opsonophagocytosis and the alternative complement pathway. The ability of FH-binding protein A (FhbA) to bind FH-like protein 1 (FHL-1) has not been assessed previously. In this study, using a whole-cell absorption assay, we demonstrated that B. hermsii absorbs both FH and FHL-1 from human serum. Consistent with this, affinity ligand binding immunoblot analyses revealed that FH constructs spanning short consensus repeats 1 to 7 and 16 to 20 bind to FhbA. To investigate the molecular basis of the interaction of FhbA with FH/FHL-1, recombinant FhbA truncated proteins were generated and tested for FH/FHL-1 binding. Binding required determinants located in both the N- and C-terminal domains of FhbA, suggesting that long-range intramolecular interactions are involved in the formation and presentation of the FH/FHL-1-binding pocket. To identify specific FhbA residues involved in binding, random mutagenesis was performed. These analyses identified a loop region of FhbA that may serve as a contact point for FH/FHL-1. The data presented here expand our understanding of the pathogenic mechanisms of the relapsing fever spirochetes and of the molecular nature of the interaction between FH/FHL-1 and FhbA.
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Affiliation(s)
- Kelley M Hovis
- Department of Microbiology and Immunology, Medical College of Virginia at Virginia Commonwealth University, Richmond, VA 23298-0678, USA
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38
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Kraiczy P, Würzner R. Complement escape of human pathogenic bacteria by acquisition of complement regulators. Mol Immunol 2006; 43:31-44. [PMID: 16011850 DOI: 10.1016/j.molimm.2005.06.016] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Pathogenic micro-organisms employ a broad range of strategies to survive in and to persistently infect the human host. Far from being completely understood by which highly sophisticated means invading pathogens overcome the host's destructive immune defence, there is a growing body of evidence on particular mechanisms which play a pivotal role for immune evasion. This review focuses on evasion of medically and scientifically important bacteria by acquisition of host derived fluid-phase complement regulatory proteins, in particular factor H, FHL-1, and C4b binding protein. Expression of microbial surface molecules binding to human complement regulators and thus fixing them in a functionally active state allows pathogens to inhibit and finely regulate complement activation directly on their surface. Further studies on the utilization of host complement regulatory proteins will likely have a marked impact on a more efficient and specific clinical treatment.
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Affiliation(s)
- Peter Kraiczy
- Institute of Medical Microbiology, University Hospital of Frankfurt, Paul-Ehrlich-Str. 40, D-60596 Frankfurt, Germany.
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39
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Progression of disease and a remedy: Causative role of macrophages and microglia: Remedial effect of immunomodulatory and immunosuppressive therapies “in combination”. Med Hypotheses 2006; 67:736-9. [DOI: 10.1016/j.mehy.2006.06.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Revised: 06/06/2006] [Accepted: 06/06/2006] [Indexed: 11/24/2022]
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40
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McDowell JV, Lankford J, Stamm L, Sadlon T, Gordon DL, Marconi RT. Demonstration of factor H-like protein 1 binding to Treponema denticola, a pathogen associated with periodontal disease in humans. Infect Immun 2005; 73:7126-32. [PMID: 16239506 PMCID: PMC1273895 DOI: 10.1128/iai.73.11.7126-7132.2005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Treponema denticola is an important contributor to periodontal disease. In this study we investigated the ability of T. denticola to bind the complement regulatory proteins factor H and factor H-like protein 1 (FHL-1). The binding of these proteins has been demonstrated to facilitate evasion of the alternative complement cascade and/or to play a role in adherence and invasion. Here we demonstrate that T. denticola specifically binds FHL-1 via a 14-kDa, surface-exposed protein that we designated FhbB. Consistent with its FHL-1 binding specificity, FhbB binds only to factor H recombinant fragments spanning short consensus repeats (SCRs) 1 to 7 (H7 construct) and not to SCR constructs spanning SCRs 8 to 15 and 16 to 20. Binding of H7 to FhbB was inhibited by heparin. The specific involvement of SCR 7 in the interaction was demonstrated using an H7 mutant (H7AB) in which specific charged residues in SCR 7 were replaced by alanine. This construct lost FhbB binding ability. Analyses of the ability of FHL-1 bound to the surface of T. denticola to serve as a cofactor for factor I-mediated cleavage of C3b revealed that C3b is cleaved in an FHL-1/factor I-independent manner, perhaps by an unidentified protease. Based on the data presented here, we hypothesize that the primary function of FHL-1 binding by T. denticola might be to facilitate adherence to FHL-1 present on anchorage-dependent cells and in the extracellular matrix.
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Affiliation(s)
- John V McDowell
- Department of Microbiology and Immunology, P.O. Box 980678, Richmond, VA 23298-0678, USA
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41
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Jokiranta TS, Cheng ZZ, Seeberger H, Jòzsi M, Heinen S, Noris M, Remuzzi G, Ormsby R, Gordon DL, Meri S, Hellwage J, Zipfel PF. Binding of complement factor H to endothelial cells is mediated by the carboxy-terminal glycosaminoglycan binding site. THE AMERICAN JOURNAL OF PATHOLOGY 2005; 167:1173-81. [PMID: 16192651 PMCID: PMC1603661 DOI: 10.1016/s0002-9440(10)61205-9] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Factor H (FH), the major fluid phase regulator of the alternative complement pathway, mediates protection of plasma-exposed host structures. It has recently been shown that short consensus repeats 19 to 20 of FH are mutational hot spots associated with atypical hemolytic uremic syndrome (aHUS), a disease with endothelial cell damage. Domain 20 of FH contains binding sites for heparin, C3b, and the cleavage product C3d. To study the role of these binding sites in target recognition, we performed site-directed mutagenesis in domain 20 and assayed the resulting recombinant proteins. The mutant FH15-20A (substitutions R1203E, R1206E, and R1210S) bound neither heparin nor endothelial cells. Similarly, an aHUS-derived mutant FH protein (E1172Stop, lacking domain 20) failed to bind endothelial cells and showed impaired binding to heparin. Binding of FH to endothelial cells was inhibited by heparin and a specific monoclonal antibody that inhibited heparin but not C3d binding, demonstrating that the heparin site on domains 19 to 20 mediates interaction of FH to endothelial cells. Binding of FH15-20 to heparin was inhibited by several cell surface- and basement membrane-associated glycosaminoglycans, suggesting that binding site specificity is not restricted to heparin. Thus, defective heparin/glycosaminoglycan-binding site on domains 19 to 20 of FH most probably mediates complement-induced endothelial cell damage in aHUS.
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Affiliation(s)
- T Sakari Jokiranta
- Department of Bacteriology and Immunology, Haartman Institute and Huslab, FIN-00014, University of Helsinki, Helsinki, Finland.
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42
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Bhide MR, Travnicek M, Levkutova M, Curlik J, Revajova V, Levkut M. Sensitivity of Borrelia genospecies to serum complement from different animals and human: a host-pathogen relationship. ACTA ACUST UNITED AC 2005; 43:165-72. [PMID: 15681146 DOI: 10.1016/j.femsim.2004.07.012] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2004] [Revised: 07/15/2004] [Accepted: 07/23/2004] [Indexed: 11/26/2022]
Abstract
Different Borrelia species and serotypes were tested for their sensitivity to serum complement from various animals and human. Complement-mediated Borrelia killing in cattle, European bison and deer was higher irrespective of the Borrelia species whereas in other animals and human it was intermediate and Borrelia species-dependent. Activation of the alternative complement pathway by particular Borrelia strain was in correlation with its sensitivity or resistance. These results support the incompetent reservoir nature of cattle, European bison, red, roe and fallow deer, at the same time present the probable reservoir nature of mouflon, dog, wolf, cat and lynx. In short, this study reviews Borrelia-host relationship and its relevance in reservoir competence nature of animals.
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Affiliation(s)
- Mangesh R Bhide
- Department of Epizootology and Infectious Diseases, University of Veterinary Medicine, Komenskeho-73, Kosice, Slovakia.
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43
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Nunn MA, Sharma A, Paesen GC, Adamson S, Lissina O, Willis AC, Nuttall PA. Complement inhibitor of C5 activation from the soft tick Ornithodoros moubata. THE JOURNAL OF IMMUNOLOGY 2005; 174:2084-91. [PMID: 15699138 DOI: 10.4049/jimmunol.174.4.2084] [Citation(s) in RCA: 158] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Blood-feeding ticks must control C activation or be damaged by the host inflammatory response. We report the characterization and expression of a novel, relatively small, broad-acting C inhibitory protein (termed OmCI) from the soft tick Ornithodoros moubata. The native 17-kDa nonglycosylated protein inhibits both human and guinea pig classical and alternative C activation pathways. The IC50 values for each pathway were 12 and 27 nM, respectively, in hemolytic assays using human serum diluted 40-fold. The cDNA encodes a protein of 168 aa, including an 18-aa secretion signal sequence that is absent in the mature form. The inhibitor has 46% amino acid identity with moubatin, a platelet aggregation inhibitor also from O. moubata that is an outlying member of the lipocalin family. Native OmCI had no inhibitory effect on the addition of C8 and C9 to preformed C5b-C7 and C5b-C8 to form the membrane attack complex and no effect on the rate of C3a production by the C3 convertase enzymes C4bC2a, C3(H2O)Bb, or C3bBb. Both recombinant and native OmCI abolish production of C5a by human classical (C4bC3bC2a) and alternative (C3bC3bBb) C5 convertases. Addition of excess C5 but not C3 competes away the inhibitory activity of OmCI, indicating that OmCI targets C5 itself rather than inhibiting the C5 convertase C4bC3bC2a itself. Direct binding of OmCI to C5 was demonstrated by Western blotting and gel filtration chromatography using 125I-labeled proteins. OmCI is the first lipocalin family member shown to inhibit C and also the first natural inhibitor that specifically targets the C5 activation step.
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Affiliation(s)
- Miles A Nunn
- Centre for Ecology and Hydrology, Oxford, Oxford, United Kingdom.
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McDowell JV, Harlin ME, Rogers EA, Marconi RT. Putative coiled-coil structural elements of the BBA68 protein of Lyme disease spirochetes are required for formation of its factor H binding site. J Bacteriol 2005; 187:1317-23. [PMID: 15687195 PMCID: PMC545637 DOI: 10.1128/jb.187.4.1317-1323.2005] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Factor H and factor H like-protein 1 (FHL-1) are complement regulatory proteins that serve as cofactors for the factor I-mediated cleavage of C3b. Some Lyme disease and relapsing fever spirochete species bind factor H to their surface to facilitate immune evasion. The Lyme disease spirochetes produce several factor H binding proteins (FHBPs) that form two distinct classes. Class I FHBPs (OspE orthologs and paralogs) bind only factor H, while class II FHBPs (BBA68) bind both factor H and FHL-1. BBA68 belongs to a large paralogous protein family, and of these paralogs, BBA69 is the member most closely related to BBA68. To determine if BBA69 can also bind factor H, recombinant protein was generated and tested for factor H binding. BBA69 did not exhibit factor H binding ability, suggesting that among family 54 paralogs, factor H binding is unique to BBA68. To identify the determinants of BBA68 that are involved in factor H binding, truncation and site-directed mutational analyses were performed. These analyses revealed that the factor H binding site is discontinuous and provide strong evidence that coiled-coil structural elements are involved in the formation of the binding site.
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Affiliation(s)
- John V McDowell
- Department of Microbiology and Immunology, Medical College of Virginia Commonwealth University, Richmond, VA 23298, USA
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McDowell JV, Wolfgang J, Senty L, Sundy CM, Noto MJ, Marconi RT. Demonstration of the involvement of outer surface protein E coiled coil structural domains and higher order structural elements in the binding of infection-induced antibody and the complement-regulatory protein, factor H. THE JOURNAL OF IMMUNOLOGY 2005; 173:7471-80. [PMID: 15585873 DOI: 10.4049/jimmunol.173.12.7471] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Factor H (fH) is an important regulator of the alternative complement cascade. Several human pathogens have been shown to bind fH to their surface, a process that facilitates immune evasion or cell to cell interaction. Among the pathogens that bind fH are some Borrelia species associated with Lyme disease and relapsing fever. The fH-binding proteins of the Lyme spirochetes form two classes (I and II). In Borrelia burgdorferi B31MI, class I includes the outer surface protein E (OspE) paralogs, L39, N38, and P38, whereas the class II group includes A68 and additional proteins that have not yet been identified. To identify the OspE determinants involved in fH and OspE-targeting infection-induced Ab (iAb) binding, deletion, random, and site-directed mutagenesis of L39 were performed. Mutations in several different regions of L39 abolished fH and or iAb binding, indicating that separable domains and residues of OspE are required for ligand binding. Some of the mutants that lost the ability to bind fH, iAb, or both had only a single amino acid change. Site-directed mutagenesis of three putative coiled coil motifs of OspE revealed that these higher order structures are required for fH binding but not for iAb binding. The data presented within demonstrate that the binding of fH and iAb to the OspE protein is mediated by higher order structures and protein conformation. These studies advance our understanding of fH binding as a virulence mechanism and facilitate ongoing efforts to use fH-binding proteins in the development of microbial vaccines.
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MESH Headings
- Amino Acid Motifs/genetics
- Amino Acid Sequence
- Amino Acid Substitution/genetics
- Amino Acid Substitution/immunology
- Antibodies, Bacterial/biosynthesis
- Antibodies, Bacterial/metabolism
- Antigens, Bacterial/chemistry
- Antigens, Bacterial/genetics
- Antigens, Bacterial/immunology
- Antigens, Bacterial/physiology
- Bacterial Outer Membrane Proteins/chemistry
- Bacterial Outer Membrane Proteins/genetics
- Bacterial Outer Membrane Proteins/immunology
- Bacterial Outer Membrane Proteins/physiology
- Bacterial Proteins/chemistry
- Bacterial Proteins/genetics
- Bacterial Proteins/immunology
- Bacterial Proteins/physiology
- Binding Sites, Antibody/genetics
- Borrelia/genetics
- Borrelia/immunology
- Borrelia/pathogenicity
- Complement Factor H/antagonists & inhibitors
- Complement Factor H/metabolism
- DNA Mutational Analysis
- Lipoproteins/chemistry
- Lipoproteins/genetics
- Lipoproteins/immunology
- Lipoproteins/physiology
- Lyme Disease/immunology
- Lyme Disease/metabolism
- Lyme Disease/microbiology
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Protein Binding/genetics
- Protein Binding/immunology
- Protein Structure, Secondary/genetics
- Protein Structure, Tertiary/genetics
- Sequence Deletion/immunology
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Affiliation(s)
- John V McDowell
- Department of Microbiology and Immunology, Medical College of Virginia at Virginia Commonwealth University, Richmond, VA 23298, USA
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Cluss RG, Silverman DA, Stafford TR. Extracellular secretion of the Borrelia burgdorferi Oms28 porin and Bgp, a glycosaminoglycan binding protein. Infect Immun 2004; 72:6279-86. [PMID: 15501754 PMCID: PMC523065 DOI: 10.1128/iai.72.11.6279-6286.2004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Borrelia burgdorferi, the Lyme disease pathogen, cycles between its Ixodes tick vector and vertebrate hosts, adapting to vastly different biochemical environments. Spirochete gene expression as a function of temperature, pH, growth phase, and host milieu is well studied, and recent work suggests that regulatory networks are involved. Here, we examine the release of Borrelia burgdorferi strain B31 proteins into conditioned medium. Spirochetes intrinsically radiolabeled at concentrations ranging from 10(7) to 10(9) cells per ml secreted Oms28, a previously characterized outer membrane porin, into RPMI medium. As determined by immunoblotting, this secretion was not associated with outer membrane blebs or cytoplasmic contamination. A similar profile of secreted proteins was obtained for spirochetes radiolabeled in mixtures of RPMI medium and serum-free Barbour-Stoenner-Kelly (BSK II) medium. Proteomic liquid chromatography-tandem mass spectrometry analysis of tryptic fragments derived from strain B31 culture supernatants confirmed the identity of the 28-kDa species as Oms28 and revealed a 26-kDa protein as 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase (Pfs-2), previously described as Bgp, a glycosaminoglycan-binding protein. The release of Oms28 into the culture medium is more selective when the spirochetes are in logarithmic phase of growth compared to organisms obtained from stationary phase. As determined by immunoblotting, stationary-phase spirochetes released OspA, OspB, and flagellin. Oms28 secreted by strains B31, HB19, and N40 was also recovered by radioimmunoprecipitation. This is the first report of B. burgdorferi protein secretion into the extracellular environment. The possible roles of Oms28 and Bgp in the host-pathogen interaction are considered.
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Affiliation(s)
- Robert G Cluss
- Department of Chemistry and Biochemistry, Middlebury College, VT 05753, USA.
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Alitalo A, Meri T, Chen T, Lankinen H, Cheng ZZ, Jokiranta TS, Seppälä IJT, Lahdenne P, Hefty PS, Akins DR, Meri S. Lysine-dependent multipoint binding of the Borrelia burgdorferi virulence factor outer surface protein E to the C terminus of factor H. THE JOURNAL OF IMMUNOLOGY 2004; 172:6195-201. [PMID: 15128807 DOI: 10.4049/jimmunol.172.10.6195] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Serum resistance, an important virulence determinant of Borrelia burgdorferi sensu lato strains belonging to the Borrelia afzelii and B. burgdorferi sensu stricto genotypes, is related to binding of the complement inhibitor factor H to the spirochete surface protein outer surface protein E (OspE) and its homologues. In this study, we show that the C-terminal short consensus repeats 18-20 of both human and mouse factor H bind to OspE. Analogously, factor H-related protein 1, a distinct plasma protein with three short consensus repeat domains homologous to those in factor H, bound to OspE. Deleting 15-aa residues (region V) from the C terminus of the OspE paralog P21 (a 20.7-kDa OspE-paralogous surface lipoprotein in the B. burgdorferi sensu stricto 297 strain) abolished factor H binding. However, C-terminal peptides from OspE, P21, or OspEF-related protein P alone and the C-terminal deletion mutants of P21 inhibited factor H binding to OspE only partially when compared with full-length P21 or its N-terminal mutant. Alanine substitution of amino acids in peptides from the key binding regions of the OspE family indicated that several lysine residues are required for factor H binding. Thus, the borrelial OspE family proteins bind the C inhibitor factor H via multiple sites in a lysine-dependent manner. The C-terminal site V (Ala(151)-Lys(166)) is necessary, but not sufficient, for factor H binding in both rodents and humans. Identification of the necessary binding sites forms a basis for the development of vaccines that block the factor H-OspE interaction and thereby promote the killing of Borreliae.
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Affiliation(s)
- Antti Alitalo
- Department of Bacteriology and Immunology, Haartman Institute and Helsinki University Central Hospital, University of Helsinki, Helsinki, Finland
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Hovis KM, McDowell JV, Griffin L, Marconi RT. Identification and characterization of a linear-plasmid-encoded factor H-binding protein (FhbA) of the relapsing fever spirochete Borrelia hermsii. J Bacteriol 2004; 186:2612-8. [PMID: 15090501 PMCID: PMC387808 DOI: 10.1128/jb.186.9.2612-2618.2004] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In North America, tick-borne relapsing fever (TBRF) is caused by the spirochete species Borrelia hermsii, Borrelia parkeri, and Borrelia turicatae. We previously demonstrated that some isolates of B. hermsii and B. parkeri are capable of binding factor H and that cell-bound factor H can participate in the factor I-mediated cleavage of C3b. Isolates that bound factor H expressed a factor H-binding protein (FHBP) that we estimated to be approximately 19 to 20 kDa in size and thus, pending further characterization, temporarily designated FHBP19. Until this report, none of the FHBPs of the TBRF spirochetes had been characterized. Here we have recovered the gene encoding the FHBP of B. hermsii YOR from a lambda ZAP II library and determined its sequence. The gene encodes a full-length protein of 22.7 kDa, which after processing is predicted to be 20.5 kDa. This protein, which we redesignate factor H-binding protein A (FhbA), is unique to B. hermsii. Two-dimensional pulsed-field gel electrophoresis and hybridization analyses revealed that the B. hermsii gene encoding FhbA is a single genetic locus that maps to a linear plasmid of approximately 220 kb. The general properties of FhbA were also assessed. The protein was found to be surface exposed and lipidated. Analysis of the antibody response to FhbA in infected mice revealed that it is antigenic during infection, indicating expression during infection. The identification and characterization of FhbA provides further insight into the molecular mechanisms of pathogenesis of the relapsing fever spirochetes.
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Affiliation(s)
- Kelley M Hovis
- Department of Microbiology and Immunology. Center for the Study of Biological Complexity, Medical College of Virginia at Virginia Commonwealth University, 1112 E. Clay Street, Richmond, VA 23298-0678, USA
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Gelderman KA, Tomlinson S, Ross GD, Gorter A. Complement function in mAb-mediated cancer immunotherapy. Trends Immunol 2004; 25:158-64. [PMID: 15036044 DOI: 10.1016/j.it.2004.01.008] [Citation(s) in RCA: 193] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Kyra A Gelderman
- Department of Pathology L1-Q, Leiden University Medical Center, Postbox 9600, 2300 RC Leiden, The Netherlands
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