scholarly journals Borrelia burgdorferi Binding of Host Complement Regulator Factor H Is Not Required for Efficient Mammalian Infection

2007 ◽  
Vol 75 (6) ◽  
pp. 3131-3139 ◽  
Author(s):  
Michael E. Woodman ◽  
Anne E. Cooley ◽  
Jennifer C. Miller ◽  
John J. Lazarus ◽  
Kathryn Tucker ◽  
...  

ABSTRACT The causative agent of Lyme disease, Borrelia burgdorferi, is naturally resistant to its host's alternative pathway of complement-mediated killing. Several different borrelial outer surface proteins have been identified as being able to bind host factor H, a regulator of the alternative pathway, leading to a hypothesis that such binding is important for borrelial resistance to complement. To test this hypothesis, the development of B. burgdorferi infection was compared between factor H-deficient and wild-type mice. Factor B- and C3-deficient mice were also studied to determine the relative roles of the alternative and classical/lectin pathways in B. burgdorferi survival during mammalian infection. While it was predicted that B. burgdorferi should be impaired in its ability to infect factor H-deficient animals, quantitative analyses of bacterial loads indicated that those mice were infected at levels similar to those of wild-type and factor B- and C3-deficient mice. Ticks fed on infected factor H-deficient or wild-type mice all acquired similar numbers of bacteria. Indirect immunofluorescence analysis of B. burgdorferi acquired by feeding ticks from the blood of infected mice indicated that none of the bacteria had detectable levels of factor H on their outer surfaces, even though such bacteria express high levels of surface proteins capable of binding factor H. These findings demonstrate that the acquisition of host factor H is not essential for mammalian infection by B. burgdorferi and indicate that additional mechanisms are employed by the Lyme disease spirochete to evade complement-mediated killing.

2007 ◽  
Vol 75 (9) ◽  
pp. 4227-4236 ◽  
Author(s):  
Tomasz Bykowski ◽  
Michael E. Woodman ◽  
Anne E. Cooley ◽  
Catherine A. Brissette ◽  
Volker Brade ◽  
...  

ABSTRACT The Lyme disease spirochete, Borrelia burgdorferi, is largely resistant to being killed by its hosts’ alternative complement activation pathway. One possible resistance mechanism of these bacteria is to coat their surfaces with host complement regulators, such as factor H. Five different B. burgdorferi outer surface proteins having affinities for factor H have been identified: complement regulator-acquiring surface protein 1 (BbCRASP-1), encoded by cspA; BbCRASP-2, encoded by cspZ; and three closely related proteins, BbCRASP-3, -4, and -5, encoded by erpP, erpC, and erpA, respectively. We now present analyses of the recently identified BbCRASP-2 and cspZ expression patterns throughout the B. burgdorferi infectious cycle, plus novel analyses of BbCRASP-1 and erp-encoded BbCRASPs. Our results, combined with data from earlier studies, indicate that BbCRASP-2 is produced primarily during established mammalian infection, while BbCRASP-1 is produced during tick-to-mammal and mammal-to-tick transmission stages but not during established mammalian infection, and Erp-BbCRASPs are produced from the time of transmission from infected ticks into mammals until they are later acquired by other feeding ticks. Transcription of cspZ and synthesis of BbCRASP-2 were severely repressed during cultivation in laboratory medium relative to mRNA levels observed during mammalian infection, and cspZ expression was influenced by culture temperature and pH, observations which will assist identification of the mechanisms employed by B. burgdorferi to control expression of this borrelial infection-associated protein.


2002 ◽  
Vol 70 (2) ◽  
pp. 491-497 ◽  
Author(s):  
Brian Stevenson ◽  
Nazira El-Hage ◽  
Melissa A. Hines ◽  
Jennifer C. Miller ◽  
Kelly Babb

ABSTRACT The Lyme disease spirochete, Borrelia burgdorferi, is capable of infecting a wide variety of vertebrates. This broad host range implies that B. burgdorferi possesses the ability to contravene the immune defenses of many potential hosts. B. burgdorferi produces multiple different Erp proteins on its outer membrane during mammalian infection. It was reported previously that one Erp protein can bind human factor H (J. Hellwage, T. Meri, T. Heikkilä, A. Alitalo, J. Panelius, P. Lahdenne, I. J. T. Seppälä, and S. Meri, J. Biol. Chem. 276:8427–8435, 2001). In this paper we report that the ability to bind the complement inhibitor factor H is a general characteristic of Erp proteins. Furthermore, each Erp protein exhibits different relative affinities for the complement inhibitors of various potential animal hosts. The data suggest that the presence of multiple Erp proteins on the surface can allow a single B. burgdorferi bacterium to resist complement-mediated killing in any of the wide range of potential hosts that it might infect. Thus, Erp proteins likely contribute to the persistence of B. burgdorferi in nature and to the ability of this bacterium to cause Lyme disease in humans and other animals.


2001 ◽  
Vol 69 (6) ◽  
pp. 4146-4153 ◽  
Author(s):  
Kelly Babb ◽  
Nazira El-Hage ◽  
Jennifer C. Miller ◽  
James A. Carroll ◽  
Brian Stevenson

ABSTRACT Deciphering the mechanisms by which Borrelia burgdorferi controls the synthesis of proteins associated with mammalian infection will be an important step toward understanding the pathogenic properties of Lyme disease-causing bacteria. We present results of studies indicating that B. burgdorferi senses a wide variety of environmental stimuli, including soluble chemicals, which enables it to independently control synthesis of the Erp and OspC proteins. Regulation of OspC and Erp expression appears to occur at the level of transcription. In this regard, we observed that one or more DNA-binding proteins interact specifically with erppromoter DNA but not with the ospC promoter.


2008 ◽  
Vol 77 (1) ◽  
pp. 300-306 ◽  
Author(s):  
Catherine A. Brissette ◽  
Katrin Haupt ◽  
Diana Barthel ◽  
Anne E. Cooley ◽  
Amy Bowman ◽  
...  

ABSTRACT Host-derived plasmin plays a critical role in mammalian infection by Borrelia burgdorferi. The Lyme disease spirochete expresses several plasminogen-binding proteins. Bound plasminogen is converted to the serine protease plasmin and thereby may facilitate the bacterium's dissemination throughout the host by degrading extracellular matrix. In this work, we demonstrate plasminogen binding by three highly similar borrelial outer surface proteins, ErpP, ErpA, and ErpC, all of which are expressed during mammalian infection. Extensive characterization of ErpP demonstrated that this protein bound in a dose-dependent manner to lysine binding site I of plasminogen. Removal of three lysine residues from the carboxy terminus of ErpP significantly reduced binding of plasminogen, and the presence of a lysine analog, ε-aminocaproic acid, inhibited the ErpP-plasminogen interaction, thus strongly pointing to a primary role for lysine residues in plasminogen binding. Ionic interactions are not required in ErpP binding of plasminogen, as addition of excess NaCl or the polyanion heparin did not have any significant effect on binding. Plasminogen bound to ErpP could be converted to the active enzyme, plasmin. The three plasminogen-binding Erp proteins can also bind the host complement regulator factor H. Plasminogen and factor H bound simultaneously and did not compete for binding to ErpP, indicating separate binding sites for both host ligands and the ability of the borrelial surface proteins to bind both host proteins.


2015 ◽  
Vol 83 (9) ◽  
pp. 3675-3683 ◽  
Author(s):  
Rebecca Byram ◽  
Robert A. Gaultney ◽  
Angela M. Floden ◽  
Christopher Hellekson ◽  
Brandee L. Stone ◽  
...  

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-typerevAgene restored heart infectivity to wild-type levels. Additionally,revAmutants 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, whilerevAis not absolutely essential for infection, deletion ofrevAhad distinct effects on dissemination, arthritis severity, and host response.


2006 ◽  
Vol 75 (1) ◽  
pp. 325-333 ◽  
Author(s):  
Marisol A. Figueira ◽  
Sanjay Ram ◽  
Richard Goldstein ◽  
Derek W. Hood ◽  
E. Richard Moxon ◽  
...  

ABSTRACT Nontypeable (NT) Haemophilus influenzae is an important cause of otitis media in children. We have shown previously that NT H. influenzae mutants defective in their ability to sialylate lipopolysaccharide (LPS), called siaB mutants, show attenuated virulence in a chinchilla model of experimental otitis media (EOM). We show that complement is a key arm of host innate immunity against NT H. influenzae-induced EOM. Depleting complement in chinchillas by use of cobra venom factor (CoVF) rendered two otherwise avirulent siaB mutants fully virulent and able to cause EOM with severity similar to that of wild-type strains. Clearance of infection caused by siaB mutants in CoVF-treated animals coincided with reappearance of C3. Wild-type strains were more resistant to direct complement-mediated killing than their siaB mutants. The serum-resistant strain bound less C3 and C4 than the serum-sensitive strain. Neither NT H. influenzae strain tested bound factor H (alternative complement pathway regulator). Selective activation of the alternative pathway resulted in more C3 binding to siaB mutants. LPS sialylation had a more profound impact on the amount of alternative-pathway-mediated C3 binding (∼5-fold decrease in fluorescence) when LPS was the main C3 target, as occurred on the more serum-resistant strain. In contrast, only an ∼1.5-fold decrease in fluorescence intensity of C3 binding was seen with the serum-sensitive strain, where surface proteins predominantly bound C3. Differences in binding sites for C3 and C4 may account for variations in serum resistance between NT H. influenzae strains, which in turn may impact their virulence. These data demonstrate a central role for complement in innate immune defenses against NT H. influenzae infections and specifically EOM.


2008 ◽  
Vol 77 (3) ◽  
pp. 1061-1070 ◽  
Author(s):  
Kileen L. Mershon ◽  
Alex Vasuthasawat ◽  
Gregory W. Lawson ◽  
Sherie L. Morrison ◽  
David O. Beenhouwer

ABSTRACT Previous studies have shown that the alternative pathway of complement activation plays an important role in protection against infection with Cryptococcus neoformans. Cryptococcus gattii does not activate the alternative pathway as well as C. neoformans in vitro. The role of complement in C. gattii infection in vivo has not been reported. In this study, we used mice deficient in complement components to investigate the role of complement in protection against a C. gattii isolate from an ongoing outbreak in northwestern North America. While factor B-deficient mice showed an enhanced rate of death, complement component C3-deficient mice died even more rapidly, indicating that the alternative pathway was not the only complement pathway contributing to protection against disease. Both C3- and factor B-deficient mice had increased fungal burdens in comparison to wild-type mice. Histopathology revealed an overwhelming fungal burden in the lungs of these complement-deficient mice, which undoubtedly prevented efficient gas exchange, causing death. Following the fate of radiolabeled organisms showed that both factor B- and C3-deficient mice were less effective than wild-type mice in clearing organisms. However, opsonization of C. gattii with complement components was not sufficient to prolong life in mice deficient in complement. Killing of C. gattii by macrophages in vitro was decreased in the presence of serum from factor B- and C3-deficient versus wild-type mice. In conclusion, we have demonstrated that complement activation is crucial for survival in C. gattii infection. Additionally, we have shown that the alternative pathway of complement activation is not the only complement pathway contributing to protection.


2021 ◽  
Author(s):  
Fernanda Flórez-Barrós ◽  
Simon J. Freeley ◽  
El Li Tham ◽  
Michael G. Robson

Background: Anti-neutrophil cytoplasmic antibody vasculitis is characterised by antibodies to myeloperoxidase or proteinase 3. Previous work in murine anti-myeloperoxidase vasculitis has shown a role for the alternative pathway complement component factor B and the anaphylotoxin C5a. However, mice deficient in properdin, which stabilizes the alternative pathway convertase, were not protected. VISTA-deficient mice were protected in the nephrotoxic nephritis model but the role of VISTA in anti-myeloperoxidase vasculitis is unknown. Objectives: This study had two aims. Firstly, we attempted to reproduce previous findings on the role of factor B in anti-myeloperoxidase vasculitis. Secondly, we examined the role of VISTA in this model, in order to see if the protection in the nephrotoxic nephritis model extended to anti-myeloperoxidase vasculitis. Methods: Anti-myeloperoxidase vasculitis was induced in wildtype, factor B, or VISTA deficient mice. Disease was assessed by quanitfying glomerular crescents and macrophages, in addition to albuminuria and serum creatinine. Results: When wild type and factor B deficient mice were compared, there were no differences in any of the histological or biochemical parameters of disease assessed. Similarly, when wild type or VISTA defiicent mice were compared, there were no differences. Conclusions: Factor B deficient mice were not protected which is in contrast to previous studies. Therefore alternative pathway activation is not essential in this model, under the conditions used in this study. VISTA deficient mice were not protected, suggesting that therapies targetting VISTA may not be effective in vasculitis.


2020 ◽  
Author(s):  
Francesca Granata ◽  
Lorena Duca ◽  
Valentina Brancaleoni ◽  
Silvia Fustinoni ◽  
Giacomo De Luca ◽  
...  

ABSTRACTThe homeostasis of tissues in chronic disease is an important function of the alternative pathway (AP) of the complement system (CS). However, if not controlled, it may also be detrimental to healthy cells.Protoporphyria (PP) is a rare disease that causes photosensitivity at the visible light due to the accumulation of Protoporphyrin-IX in the dermis. The aim of this study was to deep the knowledge about the involvement of AP in PP photoreaction.Global radiation and UV data were provided from regional agency of environmental protection (ARPA). Properdin, Factor H (FH) and C5 levels were assessed in the serum collected during winter and summer from 19 PP patients and 13 controls..Properdin in winter and summer reflected a positive increase compared to controls. The values in summer were higher than winter. The C5 results were altered only in summer. The outcome was reversed for FH: in the winter, it was higher compared to the summer. A positive correlation was reported between properdin and C3 in summer; a negative tendency between Factor B (FB) and FH was detected.This study substantiated the differential involvement of AP depending on the increase in light exposure during the season, which was demonstrated with ARPA data. The enhanced systemic response could justify the malaise sensation of patients after long light exposure and can be exploited to elucidate the new therapeutic approach.


2006 ◽  
Vol 74 (12) ◽  
pp. 7024-7028 ◽  
Author(s):  
Evelyn Rossmann ◽  
Veronique Kitiratschky ◽  
Heidelore Hofmann ◽  
Peter Kraiczy ◽  
Markus M. Simon ◽  
...  

ABSTRACT Borrelia burgdorferi complement regulator-acquiring surface protein 1 (CRASP-1), the dominant factor H and FHL-1-binding protein of the Lyme disease spirochete B. burgdorferi, is implicated in pathogen persistence and was recently reported to be nonimmunogenic in humans. Here we show that serum samples from Lyme disease patients contain antibodies with exclusive specificity for nondenatured structural determinants of CRASP-1.


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