scholarly journals Global Analysis of Borrelia burgdorferi Genes Regulated by Mammalian Host-Specific Signals

2003 ◽  
Vol 71 (6) ◽  
pp. 3371-3383 ◽  
Author(s):  
Chad S. Brooks ◽  
P. Scott Hefty ◽  
Sarah E. Jolliff ◽  
Darrin R. Akins
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Differentially Expressed Genes ◽  
Global Analysis ◽  
Outer Membrane Proteins ◽  
Differentially Expressed ◽  
Mammalian Host ◽  
Global Changes ◽  
Cultivation System ◽  
Mammalian Infection

ABSTRACT Lyme disease is a tick-borne infection that can lead to chronic, debilitating problems if not recognized or treated appropriately. Borrelia burgdorferi, the causative agent of Lyme disease, is maintained in nature by a complex enzootic cycle involving Ixodes ticks and mammalian hosts. Many previous studies support the notion that B. burgdorferi differentially expresses numerous genes and proteins to help it adapt to growth in the mammalian host. In this regard, several studies have utilized a dialysis membrane chamber (DMC) cultivation system to generate “mammalian host-adapted” spirochetes for the identification of genes selectively expressed during mammalian infection. Here, we have exploited the DMC cultivation system in conjunction with microarray technology to examine the global changes in gene expression that occur in the mammalian host. To identify genes regulated by only mammal-specific signals and not by temperature, borrelial microarrays were hybridized with cDNA generated either from organisms temperature shifted in vitro from 23°C to 37°C or from organisms cultivated by using the DMC model system. Statistical analyses of the combined data sets revealed that 125 genes were expressed at significantly different levels in the mammalian host, with almost equivalent numbers of genes being up- or down-regulated by B. burgdorferi within DMCs compared to those undergoing temperature shift. Interestingly, during DMC cultivation, the vast majority of genes identified on the plasmids were down-regulated (79%), while the differentially expressed chromosomal genes were almost entirely up-regulated (93%). Global analysis of the upstream promoter regions of differentially expressed genes revealed that several share a common motif that may be important in transcriptional regulation during mammalian infection. Among genes with known or putative functions, the cell envelope category, which includes outer membrane proteins, was found to contain the most differentially expressed genes. The combined findings have generated a subset of genes that can now be further characterized to help define their role or roles with regard to B. burgdorferi virulence and Lyme disease pathogenesis.

scholarly journals Manganese and Zinc Regulate Virulence Determinants in Borrelia burgdorferi

2013 ◽  
Vol 81 (8) ◽  
pp. 2743-2752 ◽  
Author(s):  
Bryan Troxell ◽  
Meiping Ye ◽  
Youyun Yang ◽  
Sebastian E. Carrasco ◽  
Yongliang Lou ◽  
...  
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Critical Role ◽  
Transition Metal Ions ◽  
Mammalian Host ◽  
Virulence Determinants ◽  
Temperature Dependent ◽  
Content Type ◽  
Mammalian Infection

ABSTRACTBorrelia burgdorferi, the causative agent of Lyme disease, must adapt to two diverse niches, an arthropod vector and a mammalian host. RpoS, an alternative sigma factor, plays a central role in spirochetal adaptation to the mammalian host by governing expression of many genes important for mammalian infection.B. burgdorferiis known to be unique in metal utilization, and little is known of the role of biologically available metals inB. burgdorferi. Here, we identified two transition metal ions, manganese (Mn2+) and zinc (Zn2+), that influenced regulation of RpoS. The intracellular Mn2+level fluctuated approximately 20-fold under different conditions and inversely correlated with levels of RpoS and the major virulence factor OspC. Furthermore, an increase in intracellular Mn2+repressed temperature-dependent induction of RpoS and OspC; this repression was overcome by an excess of Zn2+. Conversely, a decrease of intracellular Mn2+by deletion of the Mn2+transporter gene,bmtA, resulted in elevated levels of RpoS and OspC. Mn2+affected RpoS through BosR, a Fur family homolog that is required forrpoSexpression: elevated intracellular Mn2+levels greatly reduced the level of BosR protein but not the level ofbosRmRNA. Thus, Mn2+and Zn2+appeared to be important in modulation of the RpoS pathway that is essential to the life cycle of the Lyme disease spirochete. This finding supports the emerging notion that transition metals such as Mn2+and Zn2+play a critical role in regulation of virulence in bacteria.

scholarly journals Borrelia burgdorferi RevA Antigen Binds Host Fibronectin

2009 ◽  
Vol 77 (7) ◽  
pp. 2802-2812 ◽  
Author(s):  
Catherine A. Brissette ◽  
Tomasz Bykowski ◽  
Anne E. Cooley ◽  
Amy Bowman ◽  
Brian Stevenson
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Surface Protein ◽  
Site Directed Mutagenesis ◽  
Heparin Binding ◽  
Amino Terminal ◽  
Ligand Interactions ◽  
Fibronectin Binding Protein ◽  
Vertebrate Hosts ◽  
Mammalian Infection

ABSTRACT Borrelia burgdorferi, the Lyme disease-causing spirochete, can persistently infect its vertebrate hosts for years. B. burgdorferi is often found associated with host connective tissue, where it interacts with components of the extracellular matrix, including fibronectin. Some years ago, a borrelial surface protein, named BBK32, was identified as a fibronectin-binding protein. However, B. burgdorferi BBK32 mutants are still able to bind fibronectin, indicating that the spirochete possesses additional mechanisms for adherence to fibronectin. We now demonstrate that RevA, an unrelated B. burgdorferi outer surface protein, binds mammalian fibronectin in a saturable manner. Site-directed mutagenesis studies identified the amino terminus of the RevA protein as being required for adhesion to fibronectin. RevA bound to the amino-terminal region of fibronectin. RevA binding to fibronectin was not inhibited by salt or heparin, suggesting that adhesin-ligand interactions are primarily nonionic and occur through the non-heparin-binding regions of the fibronectin amino-terminal domains. revA genes are widely distributed among Lyme disease spirochetes, and the present studies determined that all RevA alleles tested bound fibronectin. In addition, RevB, a paralogous protein found in a subset of B. burgdorferi strains, also bound fibronectin. We also confirmed that RevA is produced during mammalian infection but not during colonization of vector ticks and determined that revA transcription is controlled through a mechanism distinct from that of BBK32.

scholarly journals Role of the BBA64 Locus of Borrelia burgdorferi in Early Stages of Infectivity in a Murine Model of Lyme Disease

2007 ◽  
Vol 76 (1) ◽  
pp. 391-402 ◽  
Author(s):  
Mahulena Maruskova ◽  
M. Dolores Esteve-Gassent ◽  
Valerie L. Sexton ◽  
J. Seshu
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Immunoblot Analysis ◽  
Open Reading Frames ◽  
Mammalian Host ◽  
Environmental Signals ◽  
Significant Difference ◽  
Linear Plasmid 54

ABSTRACT Borrelia burgdorferi, the causative agent of Lyme disease, undergoes rapid adaptive gene expression in response to environmental signals encountered during different stages of its life cycle in the arthropod vector or the mammalian host. Among all the plasmid-encoded genes of B. burgdorferi, several linear plasmid 54 (lp54)-encoded open reading frames (ORFs) exhibit the greatest differential expression in response to mammalian host-specific temperature, pH, and other uncharacterized signals. These ORFs include members of the paralogous gene family 54 (pgf 54), such as BBA64, BBA65, and BBA66, present on lp54. In an attempt to correlate transcriptional up-regulation of these pgf 54 members to their role in infectivity, we inactivated BBA64 and characterized the phenotype of this mutant both in vitro and in vivo. There were no major differences in the protein profiles between the BBA64 mutant and the control strains, while immunoblot analysis indicated that inactivation of BBA64 resulted in increased levels of BBA65. Moreover, there was no significant difference in the ability of the BBA64 mutant to infect C3H/HeN mice compared to that of its parental or complemented control strains as determined by culturing of viable spirochetes from infected tissues. However, enumeration of spirochetes using quantitative real-time PCR revealed tissue-specific differences, suggesting a minimal role for BBA64 in the survival of B. burgdorferi in select tissues. Infectivity analysis of the BBA64 mutant suggests that B. burgdorferi may utilize multiple determinants to establish infection in mammalian hosts.

scholarly journals Evaluation of RevA, a Fibronectin-Binding Protein of Borrelia burgdorferi, as a Potential Vaccine Candidate for Lyme Disease

2013 ◽  
Vol 20 (6) ◽  
pp. 892-899 ◽  
Author(s):  
Angela M. Floden ◽  
Tammy Gonzalez ◽  
Robert A. Gaultney ◽  
Catherine A. Brissette
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Passive Immunization ◽  
Surface Protein ◽  
Surface Expression ◽  
Content Type ◽  
Good Target ◽  
Potential Vaccine ◽  
Mammalian Infection

ABSTRACTPrevious studies indicated that the Lyme disease spirocheteBorrelia burgdorferiexpresses 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 withB. burgdorferimounted 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 bactericidalin vitro. To evaluate the RevA antigen as a potential vaccine, mice were vaccinated with recombinant RevA and challenged withB. burgdorferiby inoculation with a needle or by a tick bite. Cultured tissues from all treatment groups were positive forB. burgdorferi. Vaccinated animals also appeared to have similar levels ofB. burgdorferiDNA compared to nonvaccinated controls. Despite its antigenicity, surface expression, and the production of bactericidal antibodies against it, RevA does not protect againstBorrelia burgdorferiinfection in a mouse model. However, passive immunization with anti-RevA antibodies did prevent infection, suggesting the possible utility of RevA-based immunotherapeutics or vaccine.

scholarly journals Distinct Regulatory Pathways Control Expression ofBorrelia burgdorferi Infection-Associated OspC and Erp Surface Proteins

2001 ◽  
Vol 69 (6) ◽  
pp. 4146-4153 ◽  
Author(s):  
Kelly Babb ◽  
Nazira El-Hage ◽  
Jennifer C. Miller ◽  
James A. Carroll ◽  
Brian Stevenson
Keyword(s):  
Lyme Disease ◽  
Dna Binding ◽  
Borrelia Burgdorferi ◽  
Binding Proteins ◽  
Dna Binding Proteins ◽  
Surface Proteins ◽  
Control Synthesis ◽  
Regulatory Pathways ◽  
Promoter Dna ◽  
Mammalian Infection

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.

scholarly journals RpoS Is Not Central to the General Stress Response in Borrelia burgdorferi but Does Control Expression of One or More Essential Virulence Determinants

2004 ◽  
Vol 72 (11) ◽  
pp. 6433-6445 ◽  
Author(s):  
Melissa J. Caimano ◽  
Christian H. Eggers ◽  
Karsten R. O. Hazlett ◽  
Justin D. Radolf
Keyword(s):  
Escherichia Coli ◽  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Temperature Shift ◽  
Mammalian Host ◽  
Virulence Determinants ◽  
Wild Type ◽  
Rt Pcr ◽  
Oxygen Intermediates ◽  
Wide Range

ABSTRACT Borrelia burgdorferi, the Lyme disease spirochete, undergoes dramatic changes in antigenic composition as it cycles between its arthropod and mammalian hosts. A growing body of evidence suggests that these changes reflect, at least in part, the need for spirochetes to adapt to the physiological stresses imposed by abrupt changes in environmental conditions and nutrient availability. In many microorganisms, global responses are mediated by master regulators such as alternative sigma factors, with Escherichia coli RpoS (σS) serving as a prototype. The importance of this transcriptional activator in other bacteria, coupled with the report by Hübner et al. (A. Hübner, X. Yang, D. M. Nolen, T. G. Popova, F. C. Cabello, and M. V. Norgard, Proc. Natl. Acad. Sci. USA 98:12724-12729, 2001) demonstrating that the borrelial RpoS ortholog controls expression of OspC and decorin-binding protein A (DbpA), prompted us to examine more closely the roles of RpoS-dependent and -independent differential gene expression in physiological adaptation by the Lyme disease spirochete. We observed that B. burgdorferi rpoS (rpoSBb ) was induced following temperature shift and transcript levels were further enhanced by reduced pH (pH 6.8). Using quantitative real-time reverse transcription-PCR (RT-PCR), we demonstrated that, in contrast to its ortholog (rpoSEc ) in Escherichia coli, rpoSBb was expressed at significant levels in B. burgdorferi throughout all phases of growth following temperature shift. By comparing a B. burgdorferi strain 297 rpoSBb mutant to its wild-type counterpart, we determined that RpoS Bb was not required for survival following exposure to a wide range of environmental stresses (i.e., temperature shift, serum starvation, increased osmolality, reactive oxygen intermediates, and increased or reduced oxygen tension), although the mutant was more sensitive to extremes of pH. While B. burgdorferi strains lacking RpoS were able to survive within intraperitoneal dialysis membrane chambers at a level equivalent to that of the wild type, they were avirulent in mice. Lastly, RT-PCR analysis of the ospE-ospF-elp paralogous lipoprotein families complements earlier findings that many temperature-inducible borrelial loci are controlled in an RpoS Bb -independent manner. Together, these data point to fundamental differences between the role(s) of RpoS in B. burgdorferi and that in E. coli. Rather than functioning as a master regulator, RpoS Bb appears to serve as a stress-responsive activator of a subset of virulence determinants that, together with the RpoS-independent, differentially expressed regulon, encompass the spirochete's genetic programs required for mammalian host adaptation.

scholarly journals The Borrelia burgdorferi Glycosaminoglycan Binding Protein Bgp in the B31 Strain Is Not Essential for Infectivity despite Facilitating Adherence and Tissue Colonization

2017 ◽  
Vol 86 (2) ◽  
Author(s):  
Samantha Schlachter ◽  
Janakiram Seshu ◽  
Tao Lin ◽  
Steven Norris ◽  
Nikhat Parveen
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Binding Protein ◽  
Mammalian Host ◽  
Infection Model ◽  
Binding Assays ◽  
Content Type ◽  
Mouse Infection Model ◽  
Successful Infection

ABSTRACTThe Lyme disease-causing organismBorrelia burgdorferiis transmitted into the mammalian host by an infected-tick bite. Successful infection relies on the ability of this extracellular pathogen to persist and colonize different tissues.B. burgdorferiencodes a large number of adhesins that are able to interact with host ligands to facilitate adherence and tissue colonization. Multiple glycosaminoglycan binding proteins present inB. burgdorferioffer a degree of redundancy of function during infection, and this highlights the importance of glycosaminoglycans as host cell receptors for spirochete adherence. Of particular interest in this study isBorreliaglycosaminoglycan binding protein (Bgp), which binds to heparin-related glycosaminoglycans. The properties of abgptransposon mutant and atrans-complemented derivative were compared to those of the wild-typeB. burgdorferiin thein vitrobinding assays and in infection studies using a C3H/HeJ mouse infection model. We determined that the loss of Bgp impairs spirochete adherence, infectivity, and tissue colonization, resulting in a reduction of inflammatory manifestations of Lyme disease. Although Bgp is not essential for infectivity, it is an important virulence factor ofB. burgdorferithat allows adherence and tissue colonization and contributes to disease severity.

scholarly journals Multi-organ transcriptomic landscape of Ambystoma velasci metamorphosis

2020 ◽  
Author(s):  
Palacios-Martínez Janet ◽  
Caballero-Pérez Juan ◽  
Espinal-Centeno Annie ◽  
Marquez-Chavoya Gilberto ◽  
Lomelí Hilda ◽  
...  
Keyword(s):  
Differentially Expressed Genes ◽  
Developmental Process ◽  
Global Analysis ◽  
Expression Patterns ◽  
Coronary Vessels ◽  
Aquatic Organisms ◽  
Gene Clusters ◽  
Differentially Expressed ◽  
Transcriptional Responses ◽  
Terrestrial Environment

Metamorphosis is a postembryonic developmental process that involves morphophysiological and behavioral changes, allowing organisms to adapt into a novel environment. In some amphibians, aquatic organisms undergo metamorphosis to adapt in a terrestrial environment. These organisms experience major changes in their circulatory, respiratory, digestive, excretory and reproductive systems. We performed a transcriptional global analysis of heart, lung and gills during diverse stages of Ambystoma velasci metamorphosis. In our analyses, we identified eight gene clusters for each organ, according to the expression patterns of differentially expressed genes. We found 4,064 differentially expressed genes in the heart, 4,107 in the lung and 8,265 in the gills. Among the differentially expressed genes in the heart, we observed genes involved in the differentiation of cardiomyocytes in the interatrial zone, vasculogenesis and in the maturation of coronary vessels. In the lung, we found genes differentially expressed related to angiogenesis, alveolarization and synthesis of the surfactant protein. In the case of the gills, the most prominent biological processes identified are degradation of extracellular matrix, apoptosis and keratin production. Our study sheds light on the transcriptional responses and the pathways involved in the transformation of the facultative metamorphic salamander A. velasci in an organ-specific manner.

scholarly journals Borrelia burgdorferi RevA Significantly Affects Pathogenicity and Host Response in the Mouse Model of Lyme Disease

2015 ◽  
Vol 83 (9) ◽  
pp. 3675-3683 ◽  
Author(s):  
Rebecca Byram ◽  
Robert A. Gaultney ◽  
Angela M. Floden ◽  
Christopher Hellekson ◽  
Brandee L. Stone ◽  
...  
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Host Response ◽  
Collagen Deposition ◽  
Wild Type ◽  
Content Type ◽  
Cardiac Tissues ◽  
Monocyte Chemoattractant ◽  
Bacterial Interaction ◽  
Mammalian Infection

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.

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 ◽  
...  
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Alternative Pathway ◽  
Host Factor ◽  
Factor H ◽  
Surface Proteins ◽  
Wild Type ◽  
Factor B ◽  
Mammalian Infection ◽  
Deficient Mice

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.

Sign in / Sign up

Export Citation Format

Share Document