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Rudolph MJ, Chen Y, Vorauer C, Vance DJ, Piazza CL, Willsey GG, McCarthy K, Muriuki B, Cavacini LA, Guttman M, Mantis NJ. Structure of a human monoclonal antibody in complex with Outer surface protein C (OspC) of the Lyme disease spirochete, Borreliella burgdorferi. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.29.591597. [PMID: 38746285 PMCID: PMC11092446 DOI: 10.1101/2024.04.29.591597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Lyme disease is a tick-borne, multisystem infection caused by the spirochete, Borreliella burgdorferi . Although antibodies have been implicated in the resolution of Lyme disease, the specific B cell epitopes targeted during human infections remain largely unknown. In this study, we characterized and defined the structural epitope of a patient-derived bactericidal monoclonal IgG ("B11") against Outer surface protein C (OspC), a homodimeric lipoprotein necessary for B. burgdorferi tick-mediated transmission and early-stage colonization of vertebrate hosts. High-resolution epitope mapping was accomplished through hydrogen deuterium exchange-mass spectrometry (HDX-MS) and X-ray crystallography. Structural analysis of B11 Fab-OspC A complexes revealed the B11 Fabs associated in a 1:1 stoichiometry with the lateral faces of OspC A homodimers such that the antibodies are essentially positioned perpendicular to the spirochete's outer surface. B11's primary contacts reside within the membrane proximal regions of α-helices 1 and 6 and adjacent loops 5 and 6 in one OspC A monomer. In addition, B11 spans the OspC A dimer interface, engaging opposing α-helix 1', α-helix 2', and loop 2-3' in the second OspC A monomer. The B11-OspC A structure is reminiscent of the recently solved mouse transmission blocking monoclonal IgG B5 in complex with OspC A , indicating a mode of engagement with OspC that is conserved across species. In conclusion, we provide the first detailed insight into the interaction between a functional human antibody and an immunodominant Lyme disease antigen long considered an important vaccine target.
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Castro-Padovani TN, Saylor TC, Husted OT, Krusenstjerna AC, Jusufovic N, Stevenson B. Gac Is a Transcriptional Repressor of the Lyme Disease Spirochete's OspC Virulence-Associated Surface Protein. J Bacteriol 2023; 205:e0044022. [PMID: 36920207 PMCID: PMC10127594 DOI: 10.1128/jb.00440-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 02/16/2023] [Indexed: 03/16/2023] Open
Abstract
The OspC outer-surface lipoprotein is essential for the Lyme disease spirochete's initial phase of vertebrate infection. Bacteria within the midguts of unfed ticks do not express OspC but produce high levels when ticks begin to ingest blood. Lyme disease spirochetes cease production of OspC within 1 to 2 weeks of vertebrate infection, and bacteria that fail to downregulate OspC are cleared by host antibodies. Thus, tight regulation of OspC levels is critical for survival of Lyme borreliae and, therefore, an attractive target for development of novel treatment strategies. Previous studies determined that a DNA region 5' of the ospC promoter, the ospC operator, is required for control of OspC production. Hypothesizing that the ospC operator may bind a regulatory factor, DNA affinity pulldown was performed and identified binding by the Gac protein. Gac is encoded by the C-terminal domain of the gyrA open reading frame from an internal promoter, ribosome-binding site, and initiation codon. Our analyses determined that Gac exhibits a greater affinity for ospC operator and promoter DNAs than for other tested borrelial sequences. In vitro and in vivo analyses demonstrated that Gac is a transcriptional repressor of ospC. These results constitute a substantial advance to our understanding of the mechanisms by which the Lyme disease spirochete controls production of OspC. IMPORTANCE Borrelia burgdorferi sensu lato requires its surface-exposed OspC protein in order to establish infection in humans and other vertebrate hosts. Bacteria that either do not produce OspC during transmission or fail to repress OspC after infection is established are rapidly cleared by the host. Herein, we identified a borrelial protein, Gac, that exhibits preferential affinity to the ospC promoter and 5' adjacent DNA. A combination of biochemical analyses and investigations of genetically manipulated bacteria demonstrated that Gac is a transcriptional repressor of ospC. This is a substantial advance toward understanding how the Lyme disease spirochete controls production of the essential OspC virulence factor and identifies a novel target for preventative and curative therapies.
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Affiliation(s)
- Tatiana N. Castro-Padovani
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Timothy C. Saylor
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Olivia T. Husted
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Andrew C. Krusenstjerna
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Nerina Jusufovic
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Brian Stevenson
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky, USA
- Department of Entomology, University of Kentucky College of Agriculture, Food, and Ecology, Lexington, Kentucky, USA
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Borrelia burgdorferi RevA Significantly Affects Pathogenicity and Host Response in the Mouse Model of Lyme Disease. Infect Immun 2015; 83:3675-83. [PMID: 26150536 DOI: 10.1128/iai.00530-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 06/28/2015] [Indexed: 12/28/2022] Open
Abstract
The Lyme disease spirochete, Borrelia burgdorferi, expresses RevA and numerous outer surface lipoproteins during mammalian infection. As an adhesin that promotes bacterial interaction with fibronectin, RevA is poised to interact with the extracellular matrix of the host. To further define the role(s) of RevA during mammalian infection, we created a mutant that is unable to produce RevA. The mutant was still infectious to mice, although it was significantly less well able to infect cardiac tissues. Complementation of the mutant with a wild-type revA gene restored heart infectivity to wild-type levels. Additionally, revA mutants led to increased evidence of arthritis, with increased fibrotic collagen deposition in tibiotarsal joints. The mutants also induced increased levels of the chemokine CCL2, a monocyte chemoattractant, in serum, and this increase was abolished in the complemented strain. Therefore, while revA is not absolutely essential for infection, deletion of revA had distinct effects on dissemination, arthritis severity, and host response.
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Brissette CA, Gaultney RA. That's my story, and I'm sticking to it--an update on B. burgdorferi adhesins. Front Cell Infect Microbiol 2014; 4:41. [PMID: 24772392 PMCID: PMC3982108 DOI: 10.3389/fcimb.2014.00041] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 03/18/2014] [Indexed: 11/25/2022] Open
Abstract
Adhesion is the initial event in the establishment of any infection. Borrelia burgdorferi, the etiological agent of Lyme disease, possesses myriad proteins termed adhesins that facilitate contact with its vertebrate hosts. B. burgdorferi adheres to host tissues through interactions with host cells and extracellular matrix, as well as other molecules present in serum and extracellular fluids. These interactions, both general and specific, are critical in the establishment of infection. Modulation of borrelial adhesion to host tissues affects the microorganisms's ability to colonize, disseminate, and persist. In this review, we update the current knowledge on structure, function, and role in pathogenesis of these “sticky” B. burgdorferi infection-associated proteins.
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Affiliation(s)
- Catherine A Brissette
- Department of Basic Sciences, University of North Dakota School of Medicine and Health Sciences Grand Forks, ND, USA
| | - Robert A Gaultney
- Department of Basic Sciences, University of North Dakota School of Medicine and Health Sciences Grand Forks, ND, USA
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Jutras BL, Chenail AM, Carroll DW, Miller MC, Zhu H, Bowman A, Stevenson B. Bpur, the Lyme disease spirochete's PUR domain protein: identification as a transcriptional modulator and characterization of nucleic acid interactions. J Biol Chem 2013; 288:26220-26234. [PMID: 23846702 PMCID: PMC3764826 DOI: 10.1074/jbc.m113.491357] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The PUR domain is a nucleic acid-binding motif found in critical regulatory proteins of higher eukaryotes and in certain species of bacteria. During investigations into mechanisms by which the Lyme disease spirochete controls synthesis of its Erp surface proteins, it was discovered that the borrelial PUR domain protein, Bpur, binds with high affinity to double-stranded DNA adjacent to the erp transcriptional promoter. Bpur was found to enhance the effects of the erp repressor protein, BpaB. Bpur also bound single-stranded DNA and RNA, with relative affinities RNA > double-stranded DNA > single-stranded DNA. Rational site-directed mutagenesis of Bpur identified amino acid residues and domains critical for interactions with nucleic acids, and it revealed that the PUR domain has a distinct mechanism of interaction with each type of nucleic acid ligand. These data shed light on both gene regulation in the Lyme spirochete and functional mechanisms of the widely distributed PUR domain.
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Affiliation(s)
- Brandon L Jutras
- From the Department of Microbiology, Immunology, and Molecular Genetics and
| | - Alicia M Chenail
- From the Department of Microbiology, Immunology, and Molecular Genetics and
| | - Dustin W Carroll
- the Graduate Center for Toxicology, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - M Clarke Miller
- the James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky 40202, and
| | - Haining Zhu
- the Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - Amy Bowman
- From the Department of Microbiology, Immunology, and Molecular Genetics and
| | - Brian Stevenson
- From the Department of Microbiology, Immunology, and Molecular Genetics and.
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Evaluation of RevA, a fibronectin-binding protein of Borrelia burgdorferi, as a potential vaccine candidate for lyme disease. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2013; 20:892-9. [PMID: 23595502 DOI: 10.1128/cvi.00758-12] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Previous studies indicated that the Lyme disease spirochete Borrelia burgdorferi expresses the RevA outer surface protein during mammalian infection. As an adhesin that promotes bacterial interaction with fibronectin, RevA appears to be a good target for preventive therapies. RevA proteins are highly conserved across all Lyme borreliae, and antibodies against RevA protein are cross-reactive among RevA proteins from diverse strains. Mice infected with B. burgdorferi mounted a rapid IgM response to RevA, followed by a strong IgG response that generally remained elevated for more than 12 months, suggesting continued exposure of RevA protein to the immune system. RevA antibodies were bactericidal in vitro. To evaluate the RevA antigen as a potential vaccine, mice were vaccinated with recombinant RevA and challenged with B. burgdorferi by inoculation with a needle or by a tick bite. Cultured tissues from all treatment groups were positive for B. burgdorferi. Vaccinated animals also appeared to have similar levels of B. burgdorferi DNA compared to nonvaccinated controls. Despite its antigenicity, surface expression, and the production of bactericidal antibodies against it, RevA does not protect against Borrelia burgdorferi infection in a mouse model. However, passive immunization with anti-RevA antibodies did prevent infection, suggesting the possible utility of RevA-based immunotherapeutics or vaccine.
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Floden AM, Watt JA, Brissette CA. Borrelia burgdorferi enolase is a surface-exposed plasminogen binding protein. PLoS One 2011; 6:e27502. [PMID: 22087329 PMCID: PMC3210797 DOI: 10.1371/journal.pone.0027502] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 10/18/2011] [Indexed: 12/17/2022] Open
Abstract
Borrelia burgdorferi is the causative agent of Lyme disease, the most commonly reported arthropod-borne disease in the United States. B. burgdorferi is a highly invasive bacterium, yet lacks extracellular protease activity. In order to aid in its dissemination, B. burgdorferi binds plasminogen, a component of the hosts' fibrinolytic system. Plasminogen bound to the surface of B. burgdorferi can then be activated to the protease plasmin, facilitating the bacterium's penetration of endothelial cell layers and degradation of extracellular matrix components. Enolases are highly conserved proteins with no sorting sequences or lipoprotein anchor sites, yet many bacteria have enolases bound to their outer surfaces. B. burgdorferi enolase is both a cytoplasmic and membrane associated protein. Enolases from other pathogenic bacteria are known to bind plasminogen. We confirmed the surface localization of B. burgdorferi enolase by in situ protease degradation assay and immunoelectron microscopy. We then demonstrated that B. burgdorferi enolase binds plasminogen in a dose-dependent manner. Lysine residues were critical for binding of plasminogen to enolase, as the lysine analog εaminocaproic acid significantly inhibited binding. Ionic interactions did not play a significant role in plasminogen binding by enolase, as excess NaCl had no effects on the interaction. Plasminogen bound to recombinant enolase could be converted to active plasmin. We conclude that B. burgdorferi enolase is a moonlighting cytoplasmic protein which also associates with the bacterial outer surface and facilitates binding to host plasminogen.
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Affiliation(s)
- Angela M. Floden
- Departments of Microbiology and Immunology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, United States of America
| | - John A. Watt
- Departments of Anatomy and Cell Biology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, United States of America
| | - Catherine A. Brissette
- Departments of Microbiology and Immunology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, United States of America
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Schmit VL, Patton TG, Gilmore RD. Analysis of Borrelia burgdorferi Surface Proteins as Determinants in Establishing Host Cell Interactions. Front Microbiol 2011; 2:141. [PMID: 21747816 PMCID: PMC3129520 DOI: 10.3389/fmicb.2011.00141] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Accepted: 06/14/2011] [Indexed: 11/13/2022] Open
Abstract
Borrelia burgdorferi infection causes Lyme borreliosis in humans, a condition which can involve a systemic spread of the organism to colonize various tissues and organs. If the infection is left untreated by antimicrobials, it can lead to manifestations including, arthritis, carditis, and/or neurological problems. Identification and characterization of B. burgdorferi outer membrane proteins that facilitate cellular attachment and invasion to establish infection continue to be investigated. In this study, we sought to further define putative cell binding properties of surface-exposed B. burgdorferi proteins by observing whether cellular adherence could be blocked by antibodies. B. burgdorferi mixed separately with monoclonal antibodies (mAbs) against outer surface protein (Osp) A, OspC, decorin-binding protein (Dbp) A, BBA64, and RevA antigens were incubated with human umbilical vein endothelial cells (HUVEC) and human neuroglial cells (H4). B. burgdorferi treated with anti-OspA, -DbpA, and -BBA64 mAbs showed a significant decrease in cellular association compared to controls, whereas B. burgdorferi treated with anti-OspC and anti-RevA showed no reduction in cellular attachment. Additionally, temporal transcriptional analyses revealed upregulated expression of bba64, ospA, and dbpA during coincubation with cells. Together, the data provide evidence that OspA, DbpA, and BBA64 function in host cell adherence and infection mechanisms.
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Affiliation(s)
- Virginia L Schmit
- Bacterial Diseases Branch, Division of Vector Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention Fort Collins, CO, USA
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Siegel C, Hallström T, Skerka C, Eberhardt H, Uzonyi B, Beckhaus T, Karas M, Wallich R, Stevenson B, Zipfel PF, Kraiczy P. Complement factor H-related proteins CFHR2 and CFHR5 represent novel ligands for the infection-associated CRASP proteins of Borrelia burgdorferi. PLoS One 2010; 5:e13519. [PMID: 20975954 PMCID: PMC2958145 DOI: 10.1371/journal.pone.0013519] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Accepted: 09/21/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND One virulence property of Borrelia burgdorferi is its resistance to innate immunity, in particular to complement-mediated killing. Serum-resistant B. burgdorferi express up to five distinct complement regulator-acquiring surface proteins (CRASP) which interact with complement regulator factor H (CFH) and factor H-like protein 1 (FHL1) or factor H-related protein 1 (CFHR1). In the present study we elucidate the role of the infection-associated CRASP-3 and CRASP-5 protein to serve as ligands for additional complement regulatory proteins as well as for complement resistance of B. burgdorferi. METHODOLOGY/PRINCIPAL FINDINGS To elucidate whether CRASP-5 and CRASP-3 interact with various human proteins, both borrelial proteins were immobilized on magnetic beads. Following incubation with human serum, bound proteins were eluted and separated by Glycine-SDS-PAGE. In addition to CFH and CFHR1, complement regulators CFHR2 and CFHR5 were identified as novel ligands for both borrelial proteins by employing MALDI-TOF. To further assess the contributions of CRASP-3 and CRASP-5 to complement resistance, a serum-sensitive B. garinii strain G1 which lacks all CFH-binding proteins was used as a valuable model for functional analyses. Both CRASPs expressed on the B. garinii outer surface bound CFH as well as CFHR1 and CFHR2 in ELISA. In contrast, live B. garinii bound CFHR1, CFHR2, and CFHR5 and only miniscute amounts of CFH as demonstrated by serum adsorption assays and FACS analyses. Further functional analysis revealed that upon NHS incubation, CRASP-3 or CRASP-5 expressing borreliae were killed by complement. CONCLUSIONS/SIGNIFICANCE In the absence of CFH and the presence of CFHR1, CFHR2 and CFHR5, assembly and integration of the membrane attack complex was not efficiently inhibited indicating that CFH in co-operation with CFHR1, CFHR2 and CFHR5 supports complement evasion of B. burgdorferi.
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Affiliation(s)
- Corinna Siegel
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Frankfurt/Main, Germany
| | - Teresia Hallström
- Department of Infection Biology, Leibniz-Institute for Natural Products Research and Infection Biology, Jena, Germany
| | - Christine Skerka
- Department of Infection Biology, Leibniz-Institute for Natural Products Research and Infection Biology, Jena, Germany
| | - Hannes Eberhardt
- Department of Infection Biology, Leibniz-Institute for Natural Products Research and Infection Biology, Jena, Germany
| | - Barbara Uzonyi
- Department of Infection Biology, Leibniz-Institute for Natural Products Research and Infection Biology, Jena, Germany
| | - Tobias Beckhaus
- Institute of Pharmaceutical Chemistry, Johann Wolfgang Goethe-University, Frankfurt/Main, Germany
| | - Michael Karas
- Institute of Pharmaceutical Chemistry, Johann Wolfgang Goethe-University, Frankfurt/Main, Germany
| | - Reinhard Wallich
- Institute of Immunology, University of Heidelberg, Heidelberg, Germany
| | - Brian Stevenson
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, Kentucky, United States of America
| | - Peter F. Zipfel
- Department of Infection Biology, Leibniz-Institute for Natural Products Research and Infection Biology, Jena, Germany
- Friedrich Schiller University, Jena, Germany
| | - Peter Kraiczy
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Frankfurt/Main, Germany
- * E-mail:
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von Lackum K, Ollison KM, Bykowski T, Nowalk AJ, Hughes JL, Carroll JA, Zückert WR, Stevenson B. Regulated synthesis of the Borrelia burgdorferi inner-membrane lipoprotein IpLA7 (P22, P22-A) during the Lyme disease spirochaete's mammal-tick infectious cycle. MICROBIOLOGY-SGM 2007; 153:1361-1371. [PMID: 17464050 DOI: 10.1099/mic.0.2006/003350-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Results of previous immunological studies suggested that Borrelia burgdorferi regulates synthesis of the IpLA7 lipoprotein during mammalian infection. Through combined use of quantitative reverse transcription PCR, immunofluorescence analyses, ELISA and immunoblotting, it is now demonstrated that IpLA7 is actually expressed throughout mammalian infection, as well as during transmission both from feeding ticks to naïve mice and from infected mice to naïve, feeding ticks. However, proportions of IpLA7-expressing B. burgdorferi within tick midguts declined significantly with time following completion of blood feeding. Cultured bacteria differentially expressed IpLA7 in response to changes in temperature, pH and concentration of 4,5-dihydroxy-2,3-pentanedione, the precursor of autoinducer 2, indicative of mechanisms governing IpLA7 expression. Previous studies also reported mixed results as to the cellular localization of IpLA7. It is now demonstrated that IpLA7 localizes primarily to the borrelial inner membrane and is not surface-exposed, consistent with the ability of these bacteria to produce IpLA7 throughout mammalian infection despite being the target of a robust immune response.
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Affiliation(s)
- Kate von Lackum
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Kristina M Ollison
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Tomasz Bykowski
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Andrew J Nowalk
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Jessica L Hughes
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - James A Carroll
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Wolfram R Zückert
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Brian Stevenson
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY 40536, USA
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Kraiczy P, Hartmann K, Hellwage J, Skerka C, Kirschfink M, Brade V, Zipfel PF, Wallich R, Stevenson B. Immunological characterization of the complement regulator factor H-binding CRASP and Erp proteins of Borrelia burgdorferi. Int J Med Microbiol 2004; 293 Suppl 37:152-7. [PMID: 15146998 DOI: 10.1016/s1433-1128(04)80029-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Complement activation plays an important role in the elimination of invading microorganisms. Borrelia (B.) burgdorferi sensu lato the etiological agent of Lyme borreliosis, can resist complement-mediated killing. The mechanism of complement resistance of B. burgdorferi sensu stricto apparently depends on the expression of several outer surface proteins described as CRASPs (complement regulator-acquiring surface proteins). These borrelial surface proteins are able to bind components of the complement regulatory system, factor H and/or factor H-like protein 1 (FHL-1), two crucial fluid-phase negative regulators of the alternative pathway of complement. It was previously demonstrated that one CRASP is encoded by a member of the erp gene family. The purpose of the study was to use a set of monoclonal antibodies (mAb) and polyclonal antisera to characterize the relatedness of factor H-binding CRASP and Erp proteins among several B. burgdorferi sensu stricto and B. afzelii strains. Based on the observed cross-reactivities between B. burgdorferi sensu stricto strains LW2 and PKa-1, it is concluded that BbCRASP-3 is similar to ErpP, BbCRASP-4 is structurally related to ErpC, and BbCRASP-5 is similar to ErpA. The BaCRASP-2 and BaCRASP-4 proteins of B. afzelii strain EB1 reacted with both anti-ErpA and anti-ErpP antibodies whereas BaCRASP-5 of B. afzelii strain FEM1-D15 exclusively reacted with BbCRASP-3/ErpP specific antibodies. Together, these data indicate that most of the factor H-binding CRASPs are members of the Erp protein family, which represents a polymorphic class of proteins with similar or identical immunological reactivities.
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Affiliation(s)
- Peter Kraiczy
- Institute of Medical Microbiology, University Hospital of Frankfurt, Frankfurt, Germany.
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