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Zafar K, Azuama OC, Parveen N. Current and emerging approaches for eliminating Borrelia burgdorferi and alleviating persistent Lyme disease symptoms. Front Microbiol 2024; 15:1459202. [PMID: 39345262 PMCID: PMC11427371 DOI: 10.3389/fmicb.2024.1459202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Accepted: 08/21/2024] [Indexed: 10/01/2024] Open
Abstract
Lyme disease is the most prevalent tick-borne infection caused by Borrelia burgdorferi bacteria in North America. Other Borrelia species are predominately the cause of this disease in Eurasia with some distinct and various overlapping manifestations. Consequently, caution must be exercised when comparing the disease and its manifestations and treatment regimens in North America and Europe. Diagnosis of the early Lyme disease remains difficult using the currently FDA approved serological tests in the absence of a reported tick bite or of erythema migrans in many individuals, non-specific initial symptoms, and the absence of detectable anti-Borrelia antibodies in the prepatent period of infection. Furthermore, it is difficult to distinguish persistence of infection and disease versus reinfection in the endemic regions of Lyme disease by serological assays. If early infection remains untreated, spirochetes can disseminate and could affect various organs in the body with a variety of disease manifestations including arthralgias and musculoskeletal pain, neurologic symptoms and anomalies, and acrodermatitis chronicum atrophicans (ACA) in Europe. Although most patients recover after antibiotic treatment, an estimated ∼10-20% patients in the United States show persistence of symptoms known as post-treatment Lyme disease syndrome (PTLDS). The causes and biomarkers of PTLDS are not well-defined; however, several contributing factors with inconsistent degree of supporting evidence have been suggested. These include antigenic debris, dysregulation of immunological response, bacterial persisters, or combination of these features. This review highlights currently employed treatment approaches describing different antimicrobials used, and vaccine candidates tried to prevent B. burgdorferi infection.
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Affiliation(s)
| | | | - Nikhat Parveen
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ, United States
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Gwynne PJ, Stocks KLK, Karozichian ES, Pandit A, Hu LT. Metabolic modeling predicts unique drug targets in Borrelia burgdorferi. mSystems 2023; 8:e0083523. [PMID: 37855615 PMCID: PMC10734484 DOI: 10.1128/msystems.00835-23] [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: 08/11/2023] [Accepted: 08/22/2023] [Indexed: 10/20/2023] Open
Abstract
IMPORTANCE Lyme disease is often treated using long courses of antibiotics, which can cause side effects for patients and risks the evolution of antimicrobial resistance. Narrow-spectrum antimicrobials would reduce these risks, but their development has been slow because the Lyme disease bacterium, Borrelia burgdorferi, is difficult to work with in the laboratory. To accelerate the drug discovery pipeline, we developed a computational model of B. burgdorferi's metabolism and used it to predict essential enzymatic reactions whose inhibition prevented growth in silico. These predictions were validated using small-molecule enzyme inhibitors, several of which were shown to have specific activity against B. burgdorferi. Although the specific compounds used are not suitable for clinical use, we aim to use them as lead compounds to develop optimized drugs targeting the pathways discovered here.
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Affiliation(s)
- Peter J. Gwynne
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
- Tufts Lyme Disease Initiative, Tufts University, Boston, Massachusetts, USA
| | - Kee-Lee K. Stocks
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
- Tufts Lyme Disease Initiative, Tufts University, Boston, Massachusetts, USA
| | - Elysse S. Karozichian
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
- Tufts Lyme Disease Initiative, Tufts University, Boston, Massachusetts, USA
| | - Aarya Pandit
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
- Tufts Lyme Disease Initiative, Tufts University, Boston, Massachusetts, USA
| | - Linden T. Hu
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
- Tufts Lyme Disease Initiative, Tufts University, Boston, Massachusetts, USA
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Kumaresan V, Ingle TM, Kilgore N, Zhang G, Hermann BP, Seshu J. Cellular and transcriptome signatures unveiled by single-cell RNA-Seq following ex vivo infection of murine splenocytes with Borrelia burgdorferi. Front Immunol 2023; 14:1296580. [PMID: 38149246 PMCID: PMC10749944 DOI: 10.3389/fimmu.2023.1296580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 11/06/2023] [Indexed: 12/28/2023] Open
Abstract
Introduction Lyme disease, the most common tick-borne infectious disease in the US, is caused by a spirochetal pathogen Borrelia burgdorferi (Bb). Distinct host responses are observed in susceptible and resistant strains of inbred of mice following infection with Bb reflecting a subset of inflammatory responses observed in human Lyme disease. The advent of post-genomic methodologies and genomic data sets enables dissecting the host responses to advance therapeutic options for limiting the pathogen transmission and/or treatment of Lyme disease. Methods In this study, we used single-cell RNA-Seq analysis in conjunction with mouse genomics exploiting GFP-expressing Bb to sort GFP+ splenocytes and GFP- bystander cells to uncover novel molecular and cellular signatures that contribute to early stages of immune responses against Bb. Results These data decoded the heterogeneity of splenic neutrophils, macrophages, NK cells, B cells, and T cells in C3H/HeN mice in response to Bb infection. Increased mRNA abundance of apoptosis-related genes was observed in neutrophils and macrophages clustered from GFP+ splenocytes. Moreover, complement-mediated phagocytosis-related genes such as C1q and Ficolin were elevated in an inflammatory macrophage subset, suggesting upregulation of these genes during the interaction of macrophages with Bb-infected neutrophils. In addition, the role of DUSP1 in regulating the expression of Casp3 and pro-inflammatory cytokines Cxcl1, Cxcl2, Il1b, and Ccl5 in Bb-infected neutrophils were identified. Discussion These findings serve as a growing catalog of cell phenotypes/biomarkers among murine splenocytes that can be exploited for limiting spirochetal burden to limit the transmission of the agent of Lyme disease to humans via reservoir hosts.
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Affiliation(s)
- Venkatesh Kumaresan
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Taylor MacMackin Ingle
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Nathan Kilgore
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Guoquan Zhang
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Brian P. Hermann
- Department of Neuroscience, Developmental and Regenerative Biology, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Janakiram Seshu
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antonio, San Antonio, TX, United States
- South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, United States
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Forrest IS, O’Neal AJ, Pedra JHF, Do R. Cholesterol Contributes to Risk, Severity, and Machine Learning-Driven Diagnosis of Lyme Disease. Clin Infect Dis 2023; 77:839-847. [PMID: 37227948 PMCID: PMC10506776 DOI: 10.1093/cid/ciad307] [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: 03/01/2023] [Revised: 05/09/2023] [Accepted: 05/18/2023] [Indexed: 05/27/2023] Open
Abstract
BACKGROUND Lyme disease is the most prevalent vector-borne disease in the US, yet its host factors are poorly understood and diagnostic tests are limited. We evaluated patients in a large health system to uncover cholesterol's role in the susceptibility, severity, and machine learning-based diagnosis of Lyme disease. METHODS A longitudinal health system cohort comprised 1 019 175 individuals with electronic health record data and 50 329 with linked genetic data. Associations of blood cholesterol level, cholesterol genetic scores comprising common genetic variants, and burden of rare loss-of-function (LoF) variants in cholesterol metabolism genes with Lyme disease were investigated. A portable machine learning model was constructed and tested to predict Lyme disease using routine lipid and clinical measurements. RESULTS There were 3832 cases of Lyme disease. Increasing cholesterol was associated with greater risk of Lyme disease and hypercholesterolemia was more prevalent in Lyme disease cases than in controls. Cholesterol genetic scores and rare LoF variants in CD36 and LDLR were associated with Lyme disease risk. Serological profiling of cases revealed parallel trajectories of rising cholesterol and immunoglobulin levels over the disease course, including marked increases in individuals with LoF variants and high cholesterol genetic scores. The machine learning model predicted Lyme disease solely using routine lipid panel, blood count, and metabolic measurements. CONCLUSIONS These results demonstrate the value of large-scale genetic and clinical data to reveal host factors underlying infectious disease biology, risk, and prognosis and the potential for their clinical translation to machine learning diagnostics that do not need specialized assays.
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Affiliation(s)
- Iain S Forrest
- Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Medical Scientist Training Program, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Anya J O’Neal
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Joao H F Pedra
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ron Do
- Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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Over 40 Years of Fosmidomycin Drug Research: A Comprehensive Review and Future Opportunities. Pharmaceuticals (Basel) 2022; 15:ph15121553. [PMID: 36559004 PMCID: PMC9782300 DOI: 10.3390/ph15121553] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/01/2022] [Accepted: 12/05/2022] [Indexed: 12/15/2022] Open
Abstract
To address the continued rise of multi-drug-resistant microorganisms, the development of novel drugs with new modes of action is urgently required. While humans biosynthesize the essential isoprenoid precursors isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) via the established mevalonate pathway, pathogenic protozoa and certain pathogenic eubacteria use the less well-known methylerythritol phosphate pathway for this purpose. Important pathogens using the MEP pathway are, for example, Plasmodium falciparum, Mycobacterium tuberculosis, Pseudomonas aeruginosa and Escherichia coli. The enzymes of that pathway are targets for antiinfective drugs that are exempt from target-related toxicity. 2C-Methyl-D-erythritol 4-phosphate (MEP), the second enzyme of the non-mevalonate pathway, has been established as the molecular target of fosmidomycin, an antibiotic that has so far failed to be approved as an anti-infective drug. This review describes the development and anti-infective properties of a wide range of fosmidomycin derivatives synthesized over the last four decades. Here we discuss the DXR inhibitor pharmacophore, which comprises a metal-binding group, a phosphate or phosphonate moiety and a connecting linker. Furthermore, non-fosmidomycin-based DXRi, bisubstrate inhibitors and several prodrug concepts are described. A comprehensive structure-activity relationship (SAR) of nearly all inhibitor types is presented and some novel opportunities for further drug development of DXR inhibitors are discussed.
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Stupica D, Bajrović FF, Blagus R, Cerar Kišek T, Collinet-Adler S, Ružić-Sabljić E, Velušček M. Association between statin use and clinical course, microbiologic characteristics, and long-term outcome of early Lyme borreliosis. A post hoc analysis of prospective clinical trials of adult patients with erythema migrans. PLoS One 2021; 16:e0261194. [PMID: 34914751 PMCID: PMC8675750 DOI: 10.1371/journal.pone.0261194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 11/24/2021] [Indexed: 01/02/2023] Open
Abstract
Background Statins were shown to inhibit borrelial growth in vitro and promote clearance of spirochetes in a murine model of Lyme borreliosis (LB). We investigated the impact of statin use in patients with early LB. Methods In this post-hoc analysis, the association between statin use and clinical and microbiologic characteristics was investigated in 1520 adult patients with early LB manifesting as erythema migrans (EM), enrolled prospectively in several clinical trials between June 2006 and October 2019 at a single-center university hospital. Patients were assessed at enrollment and followed for 12 months. Results Statin users were older than patients not using statins, but statin use was not associated with Borrelia seropositivity rate, Borrelia skin culture positivity rate, or disease severity as assessed by erythema size or the presence of LB-associated symptoms. The time to resolution of EM was comparable in both groups. The odds for incomplete recovery decreased with time from enrollment, were higher in women, in patients with multiple EM, and in those reporting LB-associated symptoms at enrollment, but were unaffected by statin use. Conclusion Statin use was not associated with clinical and microbiologic characteristics or long-term outcome in early LB.
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Affiliation(s)
- Daša Stupica
- Department of Infectious Diseases, University Medical Center Ljubljana, Ljubljana, Slovenia
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
- * E-mail:
| | - Fajko F. Bajrović
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
- Department of Neurology, University Medical Center Ljubljana, Ljubljana, Slovenia
| | - Rok Blagus
- Institute for Biostatistics and Medical Informatics, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
- Faculty of Sports, University of Ljubljana, Ljubljana, Slovenia
| | - Tjaša Cerar Kišek
- Institute for Microbiology and Immunology Ljubljana, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Stefan Collinet-Adler
- Department of Infectious Diseases, Park Nicollet/Health Partners, Methodist Hospital, Saint Louis Park, Minnesota, United States of America
| | - Eva Ružić-Sabljić
- Institute for Microbiology and Immunology Ljubljana, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Maša Velušček
- Department of Infectious Diseases, University Medical Center Ljubljana, Ljubljana, Slovenia
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Liotta L, Luchini A. Unconventional Approaches to Direct Detection of Borreliosis and Other Tick Borne Illnesses: A Path Forward. JOURNAL OF CELLULAR IMMUNOLOGY 2021; 3:164-172. [PMID: 34414392 PMCID: PMC8372993 DOI: 10.33696/immunology.3.094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Lance Liotta
- George Mason University, Manassas, Virginia, USA
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Seshu J, Moy BE, Ingle TM. Transformation of Borrelia burgdorferi. Curr Protoc 2021; 1:e61. [PMID: 33661557 DOI: 10.1002/cpz1.61] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Transformation techniques used to genetically manipulate Borrelia burgdorferi, the agent of Lyme disease, play a critical role in generating mutants that facilitate analyses of the role of genes in the pathophysiology of this bacterium. A number of borrelial mutants have been successfully isolated and characterized since the first electrotransformation procedure was established 25 years ago (Samuels, 1995). This article is directed at additional considerations for transforming infectious B. burgdorferi to generate strains retaining the plasmid profile of the parental strain, enabling analysis of transformants for in vitro and in vivo phenotypes. These methods are built on previously published protocols and are intended to add steps and tips to enhance transformation efficiency and recovery of strains amenable for studies involving colonization, survival, and transmission of B. burgdorferi during the vector and vertebrate phases of infection. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Preparation of stock cultures, propagation of spirochetes, and analysis of plasmid profiles Basic Protocol 2: Preparation of plasmid and linear DNA templates for transformation Basic Protocol 3: Transformation of B. burgdorferi Basic Protocol 4: Antibiotic selection of borrelial transformants Basic Protocol 5: Isolation of borrelial transformants in agar overlays Basic Protocol 6: Complementation of mutant borrelial strains in cis or in trans.
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Affiliation(s)
- J Seshu
- Department of Biology, South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, Texas
| | - Brian E Moy
- Department of Biology, South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, Texas
| | - Taylor MacMackin Ingle
- Department of Biology, South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, Texas
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Chen Y, Vargas SM, Smith TC, Karna SLR, MacMackin Ingle T, Wozniak KL, Wormley FL, Seshu J. Borrelia peptidoglycan interacting Protein (BpiP) contributes to the fitness of Borrelia burgdorferi against host-derived factors and influences virulence in mouse models of Lyme disease. PLoS Pathog 2021; 17:e1009535. [PMID: 33882111 PMCID: PMC8092773 DOI: 10.1371/journal.ppat.1009535] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 05/03/2021] [Accepted: 04/07/2021] [Indexed: 12/17/2022] Open
Abstract
The Peptidoglycan (PG) cell wall of the Lyme disease (LD) spirochete, Borrelia burgdorferi (Bb), contributes to structural and morphological integrity of Bb; is a persistent antigen in LD patients; and has a unique pentapeptide with L-Ornithine as the third amino acid that cross-links its glycan polymers. A borrelial homolog (BB_0167) interacted specifically with borrelilal PG via its peptidoglycan interacting motif (MHELSEKRARAIGNYL); was localized to the protoplasmic cylinder of Bb; and was designated as Borrelia peptidoglycan interacting Protein (BpiP). A bpiP mutant displayed no defect under in vitro growth conditions with similar levels of several virulence-related proteins. However, the burden of bpiP mutant in C3H/HeN mice at day 14, 28 and 62 post-infection was significantly lower compared to control strains. No viable bpiP mutant was re-isolated from any tissues at day 62 post-infection although bpiP mutant was able to colonize immunodeficient SCID at day 28 post-infection. Acquisition or transmission of bpiP mutant by Ixodes scapularis larvae or nymphs respectively, from and to mice, was significantly lower compared to control strains. Further analysis of bpiP mutant revealed increased sensitivity to vancomycin, osmotic stress, lysosomal extracts, human antimicrobial peptide cathelicidin-LL37, complement-dependent killing in the presence of day 14 post-infection mouse serum and increased internalization of CFSC-labeled bpiP mutant by macrophages and dendritic cells compared to control strains. These studies demonstrate the importance of accessory protein/s involved in sustaining integrity of PG and cell envelope during different phases of Bb infection.
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Affiliation(s)
- Yue Chen
- South Texas Center for Emerging Infectious Diseases (STCEID) and Department of Biology, The University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - Sean M. Vargas
- South Texas Center for Emerging Infectious Diseases (STCEID) and Department of Biology, The University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - Trever C. Smith
- South Texas Center for Emerging Infectious Diseases (STCEID) and Department of Biology, The University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - Sai Lakshmi Rajasekhar Karna
- South Texas Center for Emerging Infectious Diseases (STCEID) and Department of Biology, The University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - Taylor MacMackin Ingle
- South Texas Center for Emerging Infectious Diseases (STCEID) and Department of Biology, The University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - Karen L. Wozniak
- South Texas Center for Emerging Infectious Diseases (STCEID) and Department of Biology, The University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - Floyd L. Wormley
- South Texas Center for Emerging Infectious Diseases (STCEID) and Department of Biology, The University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - Janakiram Seshu
- South Texas Center for Emerging Infectious Diseases (STCEID) and Department of Biology, The University of Texas at San Antonio, San Antonio, Texas, United States of America
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Helble JD, McCarthy JE, Hu LT. Interactions between Borrelia burgdorferi and its hosts across the enzootic cycle. Parasite Immunol 2021; 43:e12816. [PMID: 33368329 DOI: 10.1111/pim.12816] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 12/18/2020] [Accepted: 12/21/2020] [Indexed: 12/24/2022]
Abstract
The bacterial pathogen Borrelia burgdorferi is the causative agent of Lyme disease and is transmitted to humans through an Ixodes tick vector. B. burgdorferi is able to survive in both mammalian and tick hosts through careful modulation of its gene expression. This allows B. burgdorferi to adapt to the environmental and nutritional changes that occur when it is transmitted between the two hosts. Distinct interactions between the spirochete and its host occur at every step of the enzootic cycle and dictate the ability of the spirochete to survive until the next stage of the cycle. Studying the interface between B. burgdorferi, the Ixodes tick vector and the natural mammalian reservoirs has been made significantly more feasible through the complete genome sequences of the organisms and the advent of high throughput screening technologies. Ultimately, a thorough investigation of the interplay between the two domains (and two phyla within one domain) is necessary in order to completely understand how the pathogen is transmitted.
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Affiliation(s)
- Jennifer D Helble
- Department of Molecular Biology and Microbiology, Tufts University, Boston, MA, USA
| | - Julie E McCarthy
- Department of Molecular Biology and Microbiology, Tufts University, Boston, MA, USA
| | - Linden T Hu
- Department of Molecular Biology and Microbiology, Tufts University, Boston, MA, USA
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Samuels DS, Lybecker MC, Yang XF, Ouyang Z, Bourret TJ, Boyle WK, Stevenson B, Drecktrah D, Caimano MJ. Gene Regulation and Transcriptomics. Curr Issues Mol Biol 2020; 42:223-266. [PMID: 33300497 DOI: 10.21775/cimb.042.223] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Borrelia (Borreliella) burgdorferi, along with closely related species, is the etiologic agent of Lyme disease. The spirochete subsists in an enzootic cycle that encompasses acquisition from a vertebrate host to a tick vector and transmission from a tick vector to a vertebrate host. To adapt to its environment and persist in each phase of its enzootic cycle, B. burgdorferi wields three systems to regulate the expression of genes: the RpoN-RpoS alternative sigma factor cascade, the Hk1/Rrp1 two-component system and its product c-di-GMP, and the stringent response mediated by RelBbu and DksA. These regulatory systems respond to enzootic phase-specific signals and are controlled or fine- tuned by transcription factors, including BosR and BadR, as well as small RNAs, including DsrABb and Bb6S RNA. In addition, several other DNA-binding and RNA-binding proteins have been identified, although their functions have not all been defined. Global changes in gene expression revealed by high-throughput transcriptomic studies have elucidated various regulons, albeit technical obstacles have mostly limited this experimental approach to cultivated spirochetes. Regardless, we know that the spirochete, which carries a relatively small genome, regulates the expression of a considerable number of genes required for the transitions between the tick vector and the vertebrate host as well as the adaptation to each.
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Affiliation(s)
- D Scott Samuels
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Meghan C Lybecker
- Department of Biology, University of Colorado, Colorado Springs, CO 80918, USA
| | - X Frank Yang
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Zhiming Ouyang
- Department of Molecular Medicine, University of South Florida, Tampa, FL 33612, USA
| | - Travis J Bourret
- Department of Medical Microbiology and Immunology, Creighton University, Omaha, NE, 68105 USA
| | - William K Boyle
- Department of Medical Microbiology and Immunology, Creighton University, Omaha, NE, 68105 USA
| | - Brian Stevenson
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky School of Medicine, Lexington, KY 40536, USA
| | - Dan Drecktrah
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Melissa J Caimano
- Departments of Medicine, Pediatrics, and Molecular Biology and Biophysics, UConn Health, Farmington, CT, USA
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Kerstholt M, Netea MG, Joosten LAB. Borrelia burgdorferi hijacks cellular metabolism of immune cells: Consequences for host defense. Ticks Tick Borne Dis 2020; 11:101386. [PMID: 32035898 DOI: 10.1016/j.ttbdis.2020.101386] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 01/15/2020] [Accepted: 01/24/2020] [Indexed: 12/19/2022]
Abstract
Changes in cellular metabolism have proven to be important factors in driving cell behavior. It has been shown that cellular metabolism of immune cells changes when exposed to or infected by several pathogens: while this is often an adaptation of the host cells to the infection, sometimes it represents a mechanism through which the pathogens evade immune activation. Borrelia burgdorferi sensu lato, the causative agent of Lyme borreliosis, is a pathogen that highly depends on the host to survive, as the bacterium lacks many central metabolic pathways to generate its own nutrients. It is therefore quite likely that the bacterium interacts with host cells to obtain these metabolites and thereby affects metabolism in the host. Previously, several studies have assessed metabolic pathways in B. burgdorferi s.l. and how it adapts to its different host species. However, few studies have looked into how the interaction with the bacterium might affect the host cell metabolism. In this review we present the major metabolic pathways activated during Lyme borreliosis, viewed from both bacterium and host metabolism, and we discuss how these pathways interact with each other, and how they influence pathogenesis of Lyme borreliosis.
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Affiliation(s)
- Mariska Kerstholt
- Department of Internal Medicine and Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, the Netherlands
| | - Mihai G Netea
- Department of Internal Medicine and Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, the Netherlands; Human Genomics Laboratory, Craiova University of Medicine and Pharmacy, Craiova, Romania
| | - Leo A B Joosten
- Department of Internal Medicine and Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, the Netherlands.
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Bontemps-Gallo S, Gaviard C, Richards CL, Kentache T, Raffel SJ, Lawrence KA, Schindler JC, Lovelace J, Dulebohn DP, Cluss RG, Hardouin J, Gherardini FC. Global Profiling of Lysine Acetylation in Borrelia burgdorferi B31 Reveals Its Role in Central Metabolism. Front Microbiol 2018; 9:2036. [PMID: 30233522 PMCID: PMC6127242 DOI: 10.3389/fmicb.2018.02036] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 08/13/2018] [Indexed: 12/21/2022] Open
Abstract
The post-translational modification of proteins has been shown to be extremely important in prokaryotes. Using a highly sensitive mass spectrometry-based proteomics approach, we have characterized the acetylome of B. burgdorferi. As previously reported for other bacteria, a relatively low number (5%) of the potential genome-encoded proteins of B. burgdorferi were acetylated. Of these, the vast majority were involved in central metabolism and cellular information processing (transcription, translation, etc.). Interestingly, these critical cell functions were targeted during both ML (mid-log) and S (stationary) phases of growth. However, acetylation of target proteins in ML phase was limited to single lysine residues while these same proteins were acetylated at multiple sites during S phase. To determine the acetyl donor in B. burgdorferi, we used mutants that targeted the sole acetate metabolic/anabolic pathway in B. burgdorferi (lipid I synthesis). B. burgdorferi strains B31-A3, B31-A3 ΔackA (acetyl-P- and acetyl-CoA-) and B31-A3 Δpta (acetyl-P+ and acetyl-CoA-) were grown to S phase and the acetylation profiles were analyzed. While only two proteins were acetylated in the ΔackA mutant, 140 proteins were acetylated in the Δpta mutant suggesting that acetyl-P was the primary acetyl donor in B. burgdorferi. Using specific enzymatic assays, we were able to demonstrate that hyperacetylation of proteins in S phase appeared to play a role in decreasing the enzymatic activity of at least two glycolytic proteins. Currently, we hypothesize that acetylation is used to modulate enzyme activities during different stages of growth. This strategy would allow the bacteria to post-translationally stimulate the activity of key glycolytic enzymes by deacetylation rather than expending excessive energy synthesizing new proteins. This would be an appealing, low-energy strategy for a bacterium with limited metabolic capabilities. Future work focuses on identifying potential protein deacetylase(s) to complete our understanding of this important biological process.
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Affiliation(s)
- Sébastien Bontemps-Gallo
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Charlotte Gaviard
- CNRS UMR 6270 Polymères, Biopolymères, Surfaces Laboratory, Université de Rouen, Mont-Saint-Aignan, France.,PISSARO Proteomic Facility, Institut de Recherche et d'Innovation Biomédicale, Mont-Saint-Aignan, France
| | - Crystal L Richards
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Takfarinas Kentache
- CNRS UMR 6270 Polymères, Biopolymères, Surfaces Laboratory, Université de Rouen, Mont-Saint-Aignan, France.,PISSARO Proteomic Facility, Institut de Recherche et d'Innovation Biomédicale, Mont-Saint-Aignan, France
| | - Sandra J Raffel
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Kevin A Lawrence
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Joseph C Schindler
- Department of Chemistry and Biochemistry, Middlebury College, Middlebury, VT, United States
| | - Joseph Lovelace
- Department of Chemistry and Biochemistry, Middlebury College, Middlebury, VT, United States
| | - Daniel P Dulebohn
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Robert G Cluss
- Department of Chemistry and Biochemistry, Middlebury College, Middlebury, VT, United States
| | - Julie Hardouin
- CNRS UMR 6270 Polymères, Biopolymères, Surfaces Laboratory, Université de Rouen, Mont-Saint-Aignan, France.,PISSARO Proteomic Facility, Institut de Recherche et d'Innovation Biomédicale, Mont-Saint-Aignan, France
| | - Frank C Gherardini
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
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14
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Short-Chain Fatty Acids Alter Metabolic and Virulence Attributes of Borrelia burgdorferi. Infect Immun 2018; 86:IAI.00217-18. [PMID: 29891543 DOI: 10.1128/iai.00217-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 06/06/2018] [Indexed: 12/22/2022] Open
Abstract
Borrelia burgdorferi responds to a variety of host-derived factors and appropriately alters its gene expression for adaptation under different host-specific conditions. We previously showed that various levels of acetate, a short-chain fatty acid (SCFA), altered the protein profile of B. burgdorferi In this study, we determined the effects of other physiologically relevant SCFAs in the regulation of metabolic/virulence-associated proteins using mutant borrelial strains. No apparent increase in the synthesis of outer surface protein C (OspC) was noted when a carbon storage regulator A (csrA of B. burgdorferi, or csrABb ) mutant (mt) was propagated within dialysis membrane chambers implanted within rat peritoneal cavity, while the parental wild type (wt; B31-A3 strain) and csrABb cis-complemented strain (ct) had increased OspC with a reciprocal reduction in OspA levels. Growth rates of wt, mt, ct, 7D (csrABb mutant lacking 7 amino acids at the C terminus), and 8S (csrABb with site-specific changes altering its RNA-binding properties) borrelial strains were similar in the presence of acetate. Increased levels of propionate and butyrate reduced the growth rates of all strains tested, with mt and 8S exhibiting profound growth deficits at higher concentrations of propionate. Transcriptional levels of rpoS and ospC were elevated on supplementation of SCFAs compared to those of untreated spirochetes. Immunoblot analysis revealed elevated levels of RpoS, OspC, and DbpA with increased levels of SCFAs. Physiological levels of SCFAs prevalent in select human and rodent fluids were synergistic with mammalian host temperature and pH to increase the levels of aforementioned proteins, which could impact the colonization of B. burgdorferi during the mammalian phase of infection.
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15
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Borrelia Host Adaptation Protein (BadP) Is Required for the Colonization of a Mammalian Host by the Agent of Lyme Disease. Infect Immun 2018; 86:IAI.00057-18. [PMID: 29685985 DOI: 10.1128/iai.00057-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 04/17/2018] [Indexed: 11/20/2022] Open
Abstract
Borrelia burgdorferi, the agent of Lyme disease (LD), uses host-derived signals to modulate gene expression during the vector and mammalian phases of infection. Microarray analysis of mutants lacking the B orrelia host adaptation regulator (BadR) revealed the downregulation of genes encoding enzymes whose role in the pathophysiology of B. burgdorferi is unknown. Immunoblot analysis of the badR mutants confirmed reduced levels of these enzymes, and one of these enzymes, encoded by bb0086, shares homology to prokaryotic magnesium chelatase and Lon-type proteases. The BB0086 levels in B. burgdorferi were higher under conditions mimicking those in fed ticks. Mutants lacking bb0086 had no apparent in vitro growth defect but were incapable of colonizing immunocompetent C3H/HeN or immunodeficient SCID mice. Immunoblot analysis revealed reduced levels of proteins critical for the adaptation of B. burgdorferi to the mammalian host, such as OspC, DbpA, and BBK32. Both RpoS and BosR, key regulators of gene expression in B. burgdorferi, were downregulated in the bb0086 mutants. Therefore, we designated BB0086 the B orrelia host adaptation protein (BadP). Unlike badP mutants, the control strains established infection in C3H/HeN mice at 4 days postinfection, indicating an early colonization defect in mutants due to reduced levels of the lipoproteins/regulators critical for initial stages of infection. However, badP mutants survived within dialysis membrane chambers (DMCs) implanted within the rat peritoneal cavity but, unlike the control strains, did not display complete switching of OspA to OspC, suggesting incomplete adaptation to the mammalian phase of infection. These findings have opened a novel regulatory mechanism which impacts the virulence potential of B burgdorferi.
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Zhou B, Yang Y, Chen T, Lou Y, Yang XF. The oligopeptide ABC transporter OppA4 negatively regulates the virulence factor OspC production of the Lyme disease pathogen. Ticks Tick Borne Dis 2018; 9:1343-1349. [PMID: 29921537 DOI: 10.1016/j.ttbdis.2018.06.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 06/06/2018] [Accepted: 06/13/2018] [Indexed: 12/18/2022]
Abstract
Borrelia burgdorferi sensu lato, the agent of Lyme disease, exists in nature through a complex enzootic life cycle that involves both ticks and mammals. The B. burgdorferi genome encodes five Oligopeptide ABC transporters (Opp) that are predicted to be involve in transport of various nutrients. Previously, it was reported that OppA5 is important for the optimal production of OspC, a major virulence factor of B. burgdorferi. In this study, possible role of another Oligopeptide ABC transporter, OppA4 in ospC expression was investigated by construction of an oppA4 deletion mutant and the complemented strain. Inactivation of oppA4 resulted an increased production of OspC, suggesting that OppA4 has a negative impact on ospC expression. Expression of ospC is controlled by Rrp2-RpoN-RpoS, the central pathway essential for mammal infection. We showed that increased ospC expression in the oppA4 mutant was due to an increased rpoS expression. We then further investigated how OppA4 negatively regulates this pathway. Two regulators, BosR and BadR, are known to positively and negatively, respectively, regulate the Rrp2-RpoN-RpoS pathway. We found that deletion of oppA4 resulted in an increased level of BosR. Previous reports showed that bosR is mainly regulated at the post-transcriptional level by other factors. However, OppA4 appears to negatively regulate bosR expression at the transcriptional level. The finding of OppA4 involved in regulation of the Rrp2-RpoN-RpoS pathway further reinforces the importance of nutritional virulence to the enzootic cycle of B. burgdorferi.
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Affiliation(s)
- Bibi Zhou
- Zhejiang Provincial Key Laboratory of Medical Genetics, Key Laboratory of Laboratory Medicine, Ministry of Education, China, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Youyun Yang
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Tong Chen
- Zhejiang Provincial Key Laboratory of Medical Genetics, Key Laboratory of Laboratory Medicine, Ministry of Education, China, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yongliang Lou
- Zhejiang Provincial Key Laboratory of Medical Genetics, Key Laboratory of Laboratory Medicine, Ministry of Education, China, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China.
| | - X Frank Yang
- Zhejiang Provincial Key Laboratory of Medical Genetics, Key Laboratory of Laboratory Medicine, Ministry of Education, China, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, United States.
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17
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Abstract
Bioinformatic approaches and a large volume of prokaryotic genome sequences have enabled rapid identification of regulatory proteins with features to bind DNA or RNA in a given prokaryote. However, biological relevance of these regulatory proteins requires methods to rapidly purify and determine their binding properties within the physiological context or life style of the organism. Here, we describe the experimental approaches to determine the nucleic acid binding properties of regulatory proteins of Borrelia burgdorferi using Borrelia host-adaptation Re.3gulator (BadR-a DNA binding protein) and Carbon storage regulators A of B. b urgdorferi (CsrABb-an RNA binding protein) as examples. Best laboratory practices associated with overexpression/purification of recombinant borrelial proteins, synthesis of target nucleic acid sequences, and electrophoretic mobility assays to assess the protein/nucleic acid interactions are described. The methods described are intended to facilitate empirical assessment of the binding affinity, co-factor requirements, quality of the interacting partners, and readily modifiable assay conditions to assess the binding properties to define known and unknown regulatory properties of nucleic acid binding proteins of B. burgdorferi.
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18
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Miller BR, Kung Y. Structural Features and Domain Movements Controlling Substrate Binding and Cofactor Specificity in Class II HMG-CoA Reductase. Biochemistry 2017; 57:654-662. [PMID: 29224355 DOI: 10.1021/acs.biochem.7b00999] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The key mevalonate pathway enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (HMGR) uses the cofactor NAD(P)H to reduce HMG-CoA to mevalonate in the production of countless metabolites and natural products. Although inhibition of HMGR by statin drugs is well-understood, several mechanistic details of HMGR catalysis remain unresolved, and the structural basis for the wide range of cofactor specificity for either NADH or NADPH among HMGRs from different organisms is also unknown. Here, we present crystal structures of HMGR from Streptococcus pneumoniae (SpHMGR) alongside kinetic data of the enzyme's cofactor preferences. Our structure of SpHMGR bound with its kinetically preferred NADPH cofactor suggests how NADPH-specific binding and recognition are achieved. In addition, our structure of HMG-CoA-bound SpHMGR reveals large, previously unknown conformational domain movements that may control HMGR substrate binding and enable cofactor exchange without intermediate release during the catalytic cycle. Taken together, this work provides critical new insights into both the HMGR reaction mechanism and the structural basis of cofactor specificity.
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Affiliation(s)
- Bradley R Miller
- Department of Chemistry, Bryn Mawr College , 101 North Merion Avenue, Bryn Mawr, Pennsylvania 19010, United States
| | - Yan Kung
- Department of Chemistry, Bryn Mawr College , 101 North Merion Avenue, Bryn Mawr, Pennsylvania 19010, United States
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19
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Cabello FC, Godfrey HP, Bugrysheva J, Newman SA. Sleeper cells: the stringent response and persistence in the Borreliella (Borrelia) burgdorferi enzootic cycle. Environ Microbiol 2017; 19:3846-3862. [PMID: 28836724 PMCID: PMC5794220 DOI: 10.1111/1462-2920.13897] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 08/12/2017] [Accepted: 08/17/2017] [Indexed: 12/27/2022]
Abstract
Infections with tick-transmitted Borreliella (Borrelia) burgdorferi, the cause of Lyme disease, represent an increasingly large public health problem in North America and Europe. The ability of these spirochetes to maintain themselves for extended periods of time in their tick vectors and vertebrate reservoirs is crucial for continuance of the enzootic cycle as well as for the increasing exposure of humans to them. The stringent response mediated by the alarmone (p)ppGpp has been determined to be a master regulator in B. burgdorferi. It modulates the expression of identified and unidentified open reading frames needed to deal with and overcome the many nutritional stresses and other challenges faced by the spirochete in ticks and animal reservoirs. The metabolic and morphologic changes resulting from activation of the stringent response in B. burgdorferi may also be involved in the recently described non-genetic phenotypic phenomenon of tolerance to otherwise lethal doses of antimicrobials and to other antimicrobial activities. It may thus constitute a linchpin in multiple aspects of infections with Lyme disease borrelia, providing a link between the micro-ecological challenges of its enzootic life-cycle and long-term residence in the tissues of its animal reservoirs, with the evolutionary side effect of potential persistence in incidental human hosts.
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Affiliation(s)
- Felipe C. Cabello
- Department of Microbiology and Immunology, New York Medical College, Valhalla, NY, USA
| | - Henry P. Godfrey
- Department of Pathology, New York Medical College, Valhalla, NY, USA
| | - Julia Bugrysheva
- Department of Microbiology and Immunology, New York Medical College, Valhalla, NY, USA
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Stuart A. Newman
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
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20
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Dulebohn DP, Richards CL, Su H, Lawrence KA, Gherardini FC. Weak Organic Acids Decrease Borrelia burgdorferi Cytoplasmic pH, Eliciting an Acid Stress Response and Impacting RpoN- and RpoS-Dependent Gene Expression. Front Microbiol 2017; 8:1734. [PMID: 29033900 PMCID: PMC5626856 DOI: 10.3389/fmicb.2017.01734] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 08/25/2017] [Indexed: 11/23/2022] Open
Abstract
The spirochete Borrelia burgdorferi survives in its tick vector, Ixodes scapularis, or within various hosts. To transition between and survive in these distinct niches, B. burgdorferi changes its gene expression in response to environmental cues, both biochemical and physiological. Exposure of B. burgdorferi to weak monocarboxylic organic acids, including those detected in the blood meal of fed ticks, decreased the cytoplasmic pH of B. burgdorferi in vitro. A decrease in the cytoplasmic pH induced the expression of genes encoding enzymes that have been shown to restore pH homeostasis in other bacteria. These include putative coupled proton/cation exchangers, a putative Na+/H+ antiporter, a neutralizing buffer transporter, an amino acid deaminase and a proton exporting vacuolar-type VoV1 ATPase. Data presented in this report suggested that the acid stress response triggered the expression of RpoN- and RpoS-dependent genes including important virulence factors such as outer surface protein C (OspC), BBA66, and some BosR (Borreliaoxidative stress regulator)-dependent genes. Because the expression of virulence factors, like OspC, are so tightly connected by RpoS to general cellular stress responses and cell physiology, it is difficult to separate transmission-promoting conditions in what is clearly a multifactorial and complex regulatory web.
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Affiliation(s)
- Daniel P Dulebohn
- Laboratory of Zoonotic Pathogens, Gene Regulation Section, Division of Intramural Research, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Crystal L Richards
- Laboratory of Zoonotic Pathogens, Gene Regulation Section, Division of Intramural Research, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Hua Su
- Laboratory of Zoonotic Pathogens, Gene Regulation Section, Division of Intramural Research, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Kevin A Lawrence
- Laboratory of Zoonotic Pathogens, Gene Regulation Section, Division of Intramural Research, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
| | - Frank C Gherardini
- Laboratory of Zoonotic Pathogens, Gene Regulation Section, Division of Intramural Research, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, United States
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21
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Hoxmeier JC, Fleshman AC, Broeckling CD, Prenni JE, Dolan MC, Gage KL, Eisen L. Metabolomics of the tick-Borrelia interaction during the nymphal tick blood meal. Sci Rep 2017; 7:44394. [PMID: 28287618 PMCID: PMC5347386 DOI: 10.1038/srep44394] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 02/07/2017] [Indexed: 02/08/2023] Open
Abstract
The causal agents of Lyme disease in North America, Borrelia burgdorferi and Borrelia mayonii, are transmitted primarily by Ixodes scapularis ticks. Due to their limited metabolic capacity, spirochetes rely on the tick blood meal for nutrients and metabolic intermediates while residing in the tick vector, competing with the tick for nutrients in the blood meal. Metabolomics is an effective methodology to explore dynamics of spirochete survival and multiplication in tick vectors before transmission to a vertebrate host via tick saliva. Using gas chromatography coupled to mass spectrometry, we identified statistically significant differences in the metabolic profile among uninfected I. scapularis nymphal ticks, B. burgdorferi-infected nymphal ticks and B. mayonii-infected nymphal ticks by measuring metabolism every 24 hours over the course of their up to 96 hour blood meals. Specifically, differences in the abundance of purines, amino acids, carbohydrates, and fatty acids during the blood meal among the three groups of nymphal ticks suggest that B. mayonii and B. burgdorferi may have different metabolic capabilities, especially during later stages of nymphal feeding. Understanding mechanisms underlying variable metabolic requirements of different Lyme disease spirochetes within tick vectors could potentially aid development of novel methods to control spirochete transmission.
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Affiliation(s)
- J Charles Hoxmeier
- Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521, USA
| | - Amy C Fleshman
- Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521, USA
| | - Corey D Broeckling
- Proteomics and Metabolomics Facility, Colorado State University, Fort Collins, CO, 80523, USA
| | - Jessica E Prenni
- Proteomics and Metabolomics Facility, Colorado State University, Fort Collins, CO, 80523, USA
| | - Marc C Dolan
- Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521, USA
| | - Kenneth L Gage
- Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521, USA
| | - Lars Eisen
- Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521, USA
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22
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Spermine and Spermidine Alter Gene Expression and Antigenic Profile of Borrelia burgdorferi. Infect Immun 2017; 85:IAI.00684-16. [PMID: 28052993 DOI: 10.1128/iai.00684-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 12/16/2016] [Indexed: 12/28/2022] Open
Abstract
Borrelia burgdorferi, the agent of Lyme disease, responds to numerous host-derived signals to alter adaptive capabilities during its enzootic cycle in an arthropod vector and mammalian host. Molecular mechanisms that enable B. burgdorferi to detect, channel, and respond to these signals have become an intense area of study for developing strategies to limit transmission/infection. Bioinformatic analysis of the borrelial genome revealed the presence of polyamine transport components (PotA, PotB, PotC, and PotD), while homologs for polyamine biosynthesis were conspicuously absent. Although potABCD is cotranscribed, the level of PotA was elevated under in vitro growth conditions mimicking unfed ticks compared to the level in fed ticks, while the levels of PotD were similar under the aforementioned conditions in B. burgdorferi Among several polyamines and polyamine precursors, supplementation of spermine or spermidine in the borrelial growth medium induced synthesis of major regulators of gene expression in B. burgdorferi, such as RpoS and BosR, with a concomitant increase in proteins that contribute to colonization and survival of B. burgdorferi in the mammalian host. Short transcripts of rpoS were elevated in response to spermidine, which was correlated with increased protein levels of RpoS. Transcriptional analysis of rpoZ and B. burgdorferirel (relBbu ; bb0198) in the presence of spermidine revealed the interplay of multiple regulatory factors in B. burgdorferi gene expression. The effect of spermidine on the levels of select borrelial proteins was also influenced by serum factors. These studies suggest that multiple host-derived signals/nutrients and their transport systems contribute to B. burgdorferi adaptation during the vector and vertebrate host phases of infection.
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23
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Regulation of Gene and Protein Expression in the Lyme Disease Spirochete. Curr Top Microbiol Immunol 2017; 415:83-112. [PMID: 29064060 DOI: 10.1007/82_2017_49] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The infectious cycle of Borrelia burgdorferi necessitates persistent infection of both vertebrates and ticks, and efficient means of transmission between those two very different types of hosts. The Lyme disease spirochete has evolved mechanisms to sense its location in the infectious cycle, and use that information to control production of the proteins and other factors required for each step. Numerous components of borrelial regulatory pathways have been characterized to date. Their effects are being pieced together, thereby providing glimpses into a complex web of cooperative and antagonistic interactions. In this chapter, we present a broad overview of B. burgdorferi gene and protein regulation during the natural infectious cycle, discussions of culture-based methods for elucidating regulatory mechanisms, and summaries of many of the known regulatory proteins and small molecules. We also highlight areas that are in need of substantially more research.
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24
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Is There Potential for Repurposing Statins as Novel Antimicrobials? Antimicrob Agents Chemother 2016; 60:5111-21. [PMID: 27324773 DOI: 10.1128/aac.00192-16] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Statins are members of a class of pharmaceutical widely used to reduce high levels of serum cholesterol. In addition, statins have so-called "pleiotropic effects," which include inflammation reduction, immunomodulation, and antimicrobial effects. An increasing number of studies are emerging which detail the attenuation of bacterial growth and in vitro and in vivo virulence by statin treatment. In this review, we describe the current information available concerning the effects of statins on bacterial infections and provide insight regarding the potential use of these compounds as antimicrobial therapeutic agents.
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25
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Caimano MJ, Drecktrah D, Kung F, Samuels DS. Interaction of the Lyme disease spirochete with its tick vector. Cell Microbiol 2016; 18:919-27. [PMID: 27147446 DOI: 10.1111/cmi.12609] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Revised: 04/27/2016] [Accepted: 05/03/2016] [Indexed: 01/01/2023]
Abstract
Borrelia burgdorferi, the causative agent of Lyme disease (along with closely related genospecies), is in the deeply branching spirochete phylum. The bacterium is maintained in nature in an enzootic cycle that involves transmission from a tick vector to a vertebrate host and acquisition from a vertebrate host to a tick vector. During its arthropod sojourn, B. burgdorferi faces a variety of stresses, including nutrient deprivation. Here, we review some of the spirochetal factors that promote persistence, maintenance and dissemination of B. burgdorferi in the tick, and then focus on the utilization of available carbohydrates as well as the exquisite regulatory systems invoked to adapt to the austere environment between blood meals and to signal species transitions as the bacteria traverse their enzootic cycle. The spirochetes shift their source of carbon and energy from glucose in the vertebrate to glycerol in the tick. Regulation of survival under limiting nutrients requires the classic stringent response in which RelBbu controls the levels of the alarmones guanosine tetraphosphate and guanosine pentaphosphate (collectively termed (p)ppGpp), while regulation at the tick-vertebrate interface as well as regulation of protective responses to the blood meal require the two-component system Hk1/Rrp1 to activate production of the second messenger cyclic-dimeric-GMP (c-di-GMP).
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Affiliation(s)
- Melissa J Caimano
- Departments of Medicine, Pediatrics, and Molecular Biology and Biophysics, UConn Health, Farmington, CT, USA
| | - Dan Drecktrah
- Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | - Faith Kung
- Department of Veterinary Medicine, University of Maryland-College Park and Virginia-Maryland Regional College of Veterinary Medicine, College Park, MD, USA
| | - D Scott Samuels
- Division of Biological Sciences, University of Montana, Missoula, MT, USA.,Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT, USA
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Van Laar TA, Hole C, Rajasekhar Karna SL, Miller CL, Reddick R, Wormley FL, Seshu J. Statins reduce spirochetal burden and modulate immune responses in the C3H/HeN mouse model of Lyme disease. Microbes Infect 2016; 18:430-435. [PMID: 26993029 DOI: 10.1016/j.micinf.2016.03.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 03/07/2016] [Indexed: 12/22/2022]
Abstract
Lyme disease (LD) is a systemic disorder caused by Borrelia burgdorferi. Lyme spirochetes encode for a functional 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGR EC 1.1.1.88) serving as a rate limiting enzyme of the mevalonate pathway that contribute to components critical for cell wall biogenesis. Statins have been shown to inhibit B. burgdorferi in vitro. Using a mouse model of Lyme disease, we found that statins contribute to reducing bacterial burden and altering the murine immune response to favor clearance of spirochetes.
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Affiliation(s)
- Tricia A Van Laar
- South Texas Center for Emerging Infectious Diseases, Center for Excellence in Infection Genomics and Department of Biology, The University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Camaron Hole
- South Texas Center for Emerging Infectious Diseases, Center for Excellence in Infection Genomics and Department of Biology, The University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - S L Rajasekhar Karna
- South Texas Center for Emerging Infectious Diseases, Center for Excellence in Infection Genomics and Department of Biology, The University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Christine L Miller
- South Texas Center for Emerging Infectious Diseases, Center for Excellence in Infection Genomics and Department of Biology, The University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Robert Reddick
- The Department of Pathology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78249, USA
| | - Floyd L Wormley
- South Texas Center for Emerging Infectious Diseases, Center for Excellence in Infection Genomics and Department of Biology, The University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - J Seshu
- South Texas Center for Emerging Infectious Diseases, Center for Excellence in Infection Genomics and Department of Biology, The University of Texas at San Antonio, San Antonio, TX 78249, USA.
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Acetyl-Phosphate Is Not a Global Regulatory Bridge between Virulence and Central Metabolism in Borrelia burgdorferi. PLoS One 2015; 10:e0144472. [PMID: 26681317 PMCID: PMC4683003 DOI: 10.1371/journal.pone.0144472] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 11/18/2015] [Indexed: 02/05/2023] Open
Abstract
In B. burgdorferi, the Rrp2-RpoN-RpoS signaling cascade is a distinctive system that coordinates the expression of virulence factors required for successful transition between its arthropod vector and mammalian hosts. Rrp2 (BB0763), an RpoN specific response regulator, is essential to activate this regulatory pathway. Previous investigations have attempted to identify the phosphate donor of Rrp2, including the cognate histidine kinase, Hk2 (BB0764), non-cognate histidine kinases such as Hk1, CheA1, and CheA2, and small molecular weight P-donors such as carbamoyl-phosphate and acetyl-phosphate (AcP). In a report by Xu et al., exogenous sodium acetate led to increased expression of RpoS and OspC and it was hypothesized this effect was due to increased levels of AcP via the enzyme AckA (BB0622). Genome analyses identified only one pathway that could generate AcP in B. burgdorferi: the acetate/mevalonate pathway that synthesizes the lipid, undecaprenyl phosphate (C55-P, lipid I), which is essential for cell wall biogenesis. To assess the role of AcP in Rrp2–dependent regulation of RpoS and OspC, we used a unique selection strategy to generate mutants that lacked ackA (bb0622: acetate to AcP) or pta (bb0589: AcP to acetyl-CoA). These mutants have an absolute requirement for mevalonate and demonstrate that ackA and pta are required for cell viability. When the ΔackA or Δpta mutant was exposed to conditions (i.e., increased temperature or cell density) that up-regulate the expression of RpoS and OspC, normal induction of those proteins was observed. In addition, adding 20mM acetate or 20mM benzoate to the growth media of B. burgdorferi strain B31 ΔackA induced the expression of RpoS and OspC. These data suggest that AcP (generated by AckA) is not directly involved in modulating the Rrp2-RpoN-RpoS regulatory pathway and that exogenous acetate or benzoate are triggering an acid stress response in B. burgdorferi.
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Drecktrah D, Lybecker M, Popitsch N, Rescheneder P, Hall LS, Samuels DS. The Borrelia burgdorferi RelA/SpoT Homolog and Stringent Response Regulate Survival in the Tick Vector and Global Gene Expression during Starvation. PLoS Pathog 2015; 11:e1005160. [PMID: 26371761 PMCID: PMC4570706 DOI: 10.1371/journal.ppat.1005160] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 08/21/2015] [Indexed: 01/09/2023] Open
Abstract
As the Lyme disease bacterium Borrelia burgdorferi traverses its enzootic cycle, alternating between a tick vector and a vertebrate host, the spirochete must adapt and persist in the tick midgut under prolonged nutrient stress between blood meals. In this study, we examined the role of the stringent response in tick persistence and in regulation of gene expression during nutrient limitation. Nutritionally starving B. burgdorferi in vitro increased the levels of guanosine tetraphosphate (ppGpp) and guanosine pentaphosphate (pppGpp), collectively referred to as (p)ppGpp, products of the bifunctional synthetase/hydrolase RelBbu (RelA/SpoT homolog). Conversely, returning B. burgdorferi to a nutrient-rich medium decreased (p)ppGpp levels. B. burgdorferi survival in ticks between the larval and nymph blood meals, and during starvation in vitro, was dependent on RelBbu. Furthermore, normal morphological conversion from a flat-wave shape to a condensed round body (RB) form during starvation was dependent on RelBbu; relBbu mutants more frequently formed RBs, but their membranes were compromised. By differential RNA sequencing analyses, we found that RelBbu regulates an extensive transcriptome, both dependent and independent of nutrient stress. The RelBbu regulon includes the glp operon, which is important for glycerol utilization and persistence in the tick, virulence factors and the late phage operon of the 32-kb circular plasmid (cp32) family. In summary, our data suggest that RelBbu globally modulates transcription in response to nutrient stress by increasing (p)ppGpp levels to facilitate B. burgdorferi persistence in the tick.
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Affiliation(s)
- Dan Drecktrah
- Division of Biological Sciences, University of Montana, Missoula, Montana, United States of America
| | - Meghan Lybecker
- Department of Biology, University of Colorado, Colorado Springs, Colorado, United States of America
- Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
| | - Niko Popitsch
- Oxford NIHR Biomedical Research Centre, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- Center for Integrative Bioinformatics Vienna, Max F. Perutz Laboratories, University of Vienna & Medical University of Vienna, Vienna, Austria
| | - Philipp Rescheneder
- Center for Integrative Bioinformatics Vienna, Max F. Perutz Laboratories, University of Vienna & Medical University of Vienna, Vienna, Austria
| | - Laura S. Hall
- Division of Biological Sciences, University of Montana, Missoula, Montana, United States of America
| | - D. Scott Samuels
- Division of Biological Sciences, University of Montana, Missoula, Montana, United States of America
- Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, Montana, United States of America
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Absence of sodA Increases the Levels of Oxidation of Key Metabolic Determinants of Borrelia burgdorferi. PLoS One 2015; 10:e0136707. [PMID: 26322513 PMCID: PMC4556403 DOI: 10.1371/journal.pone.0136707] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Accepted: 08/07/2015] [Indexed: 11/20/2022] Open
Abstract
Borrelia burgdorferi, the causative agent of Lyme disease, alters its gene expression in response to environmental signals unique to its tick vector or vertebrate hosts. B. burgdorferi carries one superoxide dismutase gene (sodA) capable of controlling intracellular superoxide levels. Previously, sodA was shown to be essential for infection of B. burgdorferi in the C3H/HeN model of Lyme disease. We employed two-dimensional electrophoresis (2-DE) and immunoblot analysis with antibodies specific to carbonylated proteins to identify targets that were differentially oxidized in the soluble fractions of the sodA mutant compared to its isogenic parental control strain following treatment with an endogenous superoxide generator, methyl viologen (MV, paraquat). HPLC-ESI-MS/MS analysis of oxidized proteins revealed that several proteins of the glycolytic pathway (BB0057, BB0020, BB0348) exhibited increased carbonylation in the sodA mutant treated with MV. Levels of ATP and NAD/NADH were reduced in the sodA mutant compared with the parental strain following treatment with MV and could be attributed to increased levels of oxidation of proteins of the glycolytic pathway. In addition, a chaperone, HtpG (BB0560), and outer surface protein A (OspA, BBA15) were also observed to be oxidized in the sodA mutant. Immunoblot analysis revealed reduced levels of Outer surface protein C (OspC), Decorin binding protein A (DbpA), fibronectin binding protein (BBK32), RpoS and BosR in the sodA mutant compared to the control strains. Viable sodA mutant spirochetes could not be recovered from both gp91/phox-⁄- and iNOS deficient mice while borrelial DNA was detected in multiple tissues samples from infected mice at significantly lower levels compared to the parental strain. Taken together, these observations indicate that the increased oxidation of select borrelial determinants and reduced levels of critical pathogenesis-associated lipoproteins contribute to the in vivo deficit of the sodA mutant in the mouse model of Lyme disease. This study, utilizing the sodA mutant, has provided insights into adaptive capabilities critical for survival of B. burgdorferi in its hosts.
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Cyclic di-GMP modulates gene expression in Lyme disease spirochetes at the tick-mammal interface to promote spirochete survival during the blood meal and tick-to-mammal transmission. Infect Immun 2015; 83:3043-60. [PMID: 25987708 DOI: 10.1128/iai.00315-15] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 05/11/2015] [Indexed: 01/02/2023] Open
Abstract
Borrelia burgdorferi, the Lyme disease spirochete, couples environmental sensing and gene regulation primarily via the Hk1/Rrp1 two-component system (TCS) and Rrp2/RpoN/RpoS pathways. Beginning with acquisition, we reevaluated the contribution of these pathways to spirochete survival and gene regulation throughout the enzootic cycle. Live imaging of B. burgdorferi caught in the act of being acquired revealed that the absence of RpoS and the consequent derepression of tick-phase genes impart a Stay signal required for midgut colonization. In addition to the behavioral changes brought on by the RpoS-off state, acquisition requires activation of cyclic di-GMP (c-di-GMP) synthesis by the Hk1/Rrp1 TCS; B. burgdorferi lacking either component is destroyed during the blood meal. Prior studies attributed this dramatic phenotype to a metabolic lesion stemming from reduced glycerol uptake and utilization. In a head-to-head comparison, however, the B. burgdorferi Δglp mutant had a markedly greater capacity to survive tick feeding than B. burgdorferi Δhk1 or Δrrp1 mutants, establishing unequivocally that glycerol metabolism is only one component of the protection afforded by c-di-GMP. Data presented herein suggest that the protective response mediated by c-di-GMP is multifactorial, involving chemotactic responses, utilization of alternate substrates for energy generation and intermediary metabolism, and remodeling of the cell envelope as a means of defending spirochetes against threats engendered during the blood meal. Expression profiling of c-di-GMP-regulated genes through the enzootic cycle supports our contention that the Hk1/Rrp1 TCS functions primarily, if not exclusively, in ticks. These data also raise the possibility that c-di-GMP enhances the expression of a subset of RpoS-dependent genes during nymphal transmission.
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Bugrysheva JV, Pappas CJ, Terekhova DA, Iyer R, Godfrey HP, Schwartz I, Cabello FC. Characterization of the RelBbu Regulon in Borrelia burgdorferi Reveals Modulation of Glycerol Metabolism by (p)ppGpp. PLoS One 2015; 10:e0118063. [PMID: 25688856 PMCID: PMC4331090 DOI: 10.1371/journal.pone.0118063] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 01/07/2015] [Indexed: 02/07/2023] Open
Abstract
The bacterial stringent response is triggered by deficiencies of available nutrients and other environmental stresses. It is mediated by 5'-triphosphate-guanosine-3'-diphosphate and 5'-diphosphate-guanosine-3'-diphosphate (collectively (p)ppGpp) and generates global changes in gene expression and metabolism that enable bacteria to adapt to and survive these challenges. Borrelia burgdorferi encounters multiple stressors in its cycling between ticks and mammals that could trigger the stringent response. We have previously shown that the B. burgdorferi stringent response is mediated by a single enzyme, RelBbu, with both (p)ppGpp synthase and hydrolase activities, and that a B. burgdorferi 297 relBbu null deletion mutant was defective in adapting to stationary phase, incapable of down-regulating synthesis of rRNA and could not infect mice. We have now used this deletion mutant and microarray analysis to identify genes comprising the rel regulon in B. burgdorferi cultured at 34°C, and found that transcription of genes involved in glycerol metabolism is induced by relBbu. Culture of the wild type parental strain, the relBbu deletion mutant and its complemented derivative at 34°C and 25°C in media containing glucose or glycerol as principal carbon sources revealed a growth defect in the mutant, most evident at the lower temperature. Transcriptional analysis of the glp operon for glycerol uptake and metabolism in these three strains confirmed that relBbu was necessary and sufficient to increase transcription of this operon in the presence of glycerol at both temperatures. These results confirm and extend previous findings regarding the stringent response in B. burgdorferi. They also demonstrate that the stringent response regulates glycerol metabolism in this organism and is likely crucial for its optimal growth in ticks.
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Affiliation(s)
- Julia V. Bugrysheva
- Department of Microbiology and Immunology, New York Medical College, Valhalla, New York, 10595, United States of America
| | - Christopher J. Pappas
- Department of Microbiology and Immunology, New York Medical College, Valhalla, New York, 10595, United States of America
| | - Darya A. Terekhova
- Department of Microbiology and Immunology, New York Medical College, Valhalla, New York, 10595, United States of America
| | - Radha Iyer
- Department of Microbiology and Immunology, New York Medical College, Valhalla, New York, 10595, United States of America
| | - Henry P. Godfrey
- Department of Pathology, New York Medical College, Valhalla, New York, 10595, United States of America
| | - Ira Schwartz
- Department of Microbiology and Immunology, New York Medical College, Valhalla, New York, 10595, United States of America
| | - Felipe C. Cabello
- Department of Microbiology and Immunology, New York Medical College, Valhalla, New York, 10595, United States of America
- * E-mail:
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Sun L, Shang F, Duan CQ, Yan GL. Reduction of fatty acid flux at low temperature led to enhancement of β-carotene biosynthesis in recombinant Saccharomyces cerevisiae. KOREAN J CHEM ENG 2015. [DOI: 10.1007/s11814-014-0318-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Iyer R, Caimano MJ, Luthra A, Axline D, Corona A, Iacobas DA, Radolf JD, Schwartz I. Stage-specific global alterations in the transcriptomes of Lyme disease spirochetes during tick feeding and following mammalian host adaptation. Mol Microbiol 2014; 95:509-38. [PMID: 25425211 DOI: 10.1111/mmi.12882] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/19/2014] [Indexed: 12/31/2022]
Abstract
Borrelia burgdorferi, the agent of Lyme disease, is maintained in nature within an enzootic cycle involving a mammalian reservoir and an Ixodes sp. tick vector. The transmission, survival and pathogenic potential of B. burgdorferi depend on the bacterium's ability to modulate its transcriptome as it transits between vector and reservoir host. Herein, we employed an amplification-microarray approach to define the B. burgdorferi transcriptomes in fed larvae, fed nymphs and in mammalian host-adapted organisms cultivated in dialysis membrane chambers. The results show clearly that spirochetes exhibit unique expression profiles during each tick stage and during cultivation within the mammal; importantly, none of these profiles resembles that exhibited by in vitro grown organisms. Profound shifts in transcript levels were observed for genes encoding known or predicted lipoproteins as well as proteins involved in nutrient uptake, carbon utilization and lipid synthesis. Stage-specific expression patterns of chemotaxis-associated genes also were noted, suggesting that the composition and interactivities of the chemotaxis machinery components vary considerably in the feeding tick and mammal. The results as a whole make clear that environmental sensing by B. burgdorferi directly or indirectly drives an extensive and tightly integrated modulation of cell envelope constituents, chemotaxis/motility machinery, intermediary metabolism and cellular physiology. These findings provide the necessary transcriptional framework for delineating B. burgdorferi regulatory pathways throughout the enzootic cycle as well as defining the contribution(s) of individual genes to spirochete survival in nature and virulence in humans.
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Affiliation(s)
- Radha Iyer
- Department of Microbiology and Immunology, New York Medical College, Valhalla, NY, USA
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Groshong AM, Blevins JS. Insights into the biology of Borrelia burgdorferi gained through the application of molecular genetics. ADVANCES IN APPLIED MICROBIOLOGY 2014; 86:41-143. [PMID: 24377854 DOI: 10.1016/b978-0-12-800262-9.00002-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Borrelia burgdorferi, the vector-borne bacterium that causes Lyme disease, was first identified in 1982. It is known that much of the pathology associated with Lyme borreliosis is due to the spirochete's ability to infect, colonize, disseminate, and survive within the vertebrate host. Early studies aimed at defining the biological contributions of individual genes during infection and transmission were hindered by the lack of adequate tools and techniques for molecular genetic analysis of the spirochete. The development of genetic manipulation techniques, paired with elucidation and annotation of the B. burgdorferi genome sequence, has led to major advancements in our understanding of the virulence factors and the molecular events associated with Lyme disease. Since the dawn of this genetic era of Lyme research, genes required for vector or host adaptation have garnered significant attention and highlighted the central role that these components play in the enzootic cycle of this pathogen. This chapter covers the progress made in the Borrelia field since the application of mutagenesis techniques and how they have allowed researchers to begin ascribing roles to individual genes. Understanding the complex process of adaptation and survival as the spirochete cycles between the tick vector and vertebrate host will lead to the development of more effective diagnostic tools as well as identification of novel therapeutic and vaccine targets. In this chapter, the Borrelia genes are presented in the context of their general biological roles in global gene regulation, motility, cell processes, immune evasion, and colonization/dissemination.
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Affiliation(s)
- Ashley M Groshong
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Jon S Blevins
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
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Nagy G, Farkas A, Csernetics Á, Bencsik O, Szekeres A, Nyilasi I, Vágvölgyi C, Papp T. Transcription of the three HMG-CoA reductase genes of Mucor circinelloides. BMC Microbiol 2014; 14:93. [PMID: 24731286 PMCID: PMC4037427 DOI: 10.1186/1471-2180-14-93] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 03/05/2014] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Precursors of sterols, carotenoids, the prenyl groups of several proteins and other terpenoid compounds are synthesised via the acetate-mevalonate pathway. One of the key enzyme of this pathway is the 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase, which catalyses the conversion of HMG-CoA to mevalonate. HMG-CoA reductase therefore affects many biological processes, such as morphogenesis, synthesis of different metabolites or adaptation to environmental changes. In this study, transcription of the three HMG-CoA reductase genes (designated as hmgR1, hmgR2 and hmgR3) of the β-carotene producing Mucor circinelloides has been analysed under various culturing conditions; effect of the elevation of their copy number on the carotenoid and ergosterol content as well as on the sensitivity to statins has also been examined. RESULTS Transcripts of each gene were detected and their relative levels varied under the tested conditions. Transcripts of hmgR1 were detected only in the mycelium and its relative transcript level seems to be strongly controlled by the temperature and the oxygen level of the environment. Transcripts of hmgR2 and hmgR3 are already present in the germinating spores and the latter is also strongly regulated by oxygen. Overexpression of hmgR2 and hmgR3 by elevating their copy numbers increased the carotenoid content of the fungus and decreased their sensitivity to statins. CONCLUSIONS The three HMG-CoA reductase genes of M. circinelloides displayed different relative transcript levels under the tested conditions suggesting differences in their regulation. They seem to be especially involved in the adaptation to the changing oxygen tension and osmotic conditions of the environment as well as to statin treatment. Overexpression of hmgR2 and hmgR3 may be used to improve the carotenoid content.
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Affiliation(s)
| | | | | | | | | | | | | | - Tamás Papp
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, Szeged, H-6726, Hungary.
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Dulebohn DP, Hayes BM, Rosa PA. Global repression of host-associated genes of the Lyme disease spirochete through post-transcriptional modulation of the alternative sigma factor RpoS. PLoS One 2014; 9:e93141. [PMID: 24671196 PMCID: PMC3966842 DOI: 10.1371/journal.pone.0093141] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 02/28/2014] [Indexed: 11/18/2022] Open
Abstract
Borrelia burgdorferi, the agent of Lyme disease, is a vector-borne pathogen that transits between Ixodes ticks and vertebrate hosts. During the natural infectious cycle, spirochetes must globally adjust their transcriptome to survive in these dissimilar environments. One way B. burgdorferi accomplishes this is through the use of alternative sigma factors to direct transcription of specific genes. RpoS, one of only three sigma factors in B. burgdorferi, controls expression of genes required during tick-transmission and infection of the mammalian host. How spirochetes switch between different sigma factors during the infectious cycle has remained elusive. Here we establish a role for a novel protein, BBD18, in the regulation of the virulence-associated sigma factor RpoS. Constitutive expression of BBD18 repressed transcription of RpoS-dependent genes to levels equivalent to those observed in an rpoS mutant. Consistent with the global loss of RpoS-dependent transcripts, we were unable to detect RpoS protein. However, constitutive expression of BBD18 did not diminish the amount of rpoS transcript, indicating post-transcriptional regulation of RpoS by BBD18. Interestingly, BBD18-mediated repression of RpoS is independent of both the rpoS promoter and the 5’ untranslated region, suggesting a mechanism of protein destabilization rather than translational control. We propose that BBD18 is a novel regulator of RpoS and its activity likely represents a first step in the transition from an RpoS-ON to an RpoS-OFF state, when spirochetes transition from the host to the tick vector.
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Affiliation(s)
- Daniel P. Dulebohn
- Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
- * E-mail:
| | - Beth M. Hayes
- Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Patricia A. Rosa
- Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
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CsrA (BB0184) is not involved in activation of the RpoN-RpoS regulatory pathway in Borrelia burgdorferi. Infect Immun 2014; 82:1511-22. [PMID: 24452681 DOI: 10.1128/iai.01555-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Borrelia burgdorferi encodes a homologue of the bacterial carbon storage regulator A (CsrA). Recently, it was reported that CsrA contributes to B. burgdorferi infectivity and is required for the activation of the central RpoN-RpoS regulatory pathway. However, many questions concerning the function of CsrA in B. burgdorferi gene regulation remain unanswered. In particular, there are conflicting reports concerning the molecular details of how CsrA may modulate rpoS expression and, thus, how CsrA may influence the RpoN-RpoS pathway in B. burgdorferi. To address these key discrepancies, we examined the role of CsrA in differential gene expression in the Lyme disease spirochete. Upon engineering an inducible csrA expression system in B. burgdorferi, controlled hyperexpression of CsrA in a merodiploid strain did not significantly alter the protein and transcript levels of bosR, rpoS, and RpoS-dependent genes (such as ospC and dbpA). In addition, we constructed isogenic csrA mutants in two widely used infectious B. burgdorferi strains. When expression of bosR, rpoS, ospC, and dbpA was compared between the csrA mutants and their wild-type counterparts, no detectable differences were observed. Finally, animal studies indicated that the csrA mutants remained infectious for and virulent in mice. Analyses of B. burgdorferi gene expression in mouse tissues showed comparable levels of rpoS transcripts by the csrA mutants and the parental strains. Taken together, these results constitute compelling evidence that CsrA is not involved in activation of the RpoN-RpoS pathway and is dispensable for mammalian infectious processes carried out by B. burgdorferi.
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Gene replacement and elimination using λRed- and FLP-based tool to re-direct carbon flux in acetogen biocatalyst during continuous CO2/H2 blend fermentation. ACTA ACUST UNITED AC 2013; 40:749-58. [DOI: 10.1007/s10295-013-1279-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Accepted: 04/23/2013] [Indexed: 10/26/2022]
Abstract
Abstract
A time- and cost-efficient two-step gene elimination procedure was used for acetogen Clostridium sp. MT1834 capable of fermenting CO2/H2 blend to 245 mM acetate (p < 0.005). The first step rendered the targeted gene replacement without affecting the total genome size. We replaced the acetate pta-ack cluster with synthetic bi-functional acetaldehyde-alcohol dehydrogenase (al-adh). Replacement of pta-ack with al-adh rendered initiation of 243 mM ethanol accumulation at the expense of acetate production during CO2/H2 blend continuous fermentation (p < 0.005). At the second step, al-adh was eliminated to reduce the genome size. Resulting recombinants accumulated 25 mM mevalonate in fermentation broth (p < 0.005). Cell duplication time for recombinants with reduced genome size decreased by 9.5 % compared to Clostridium sp. MT1834 strain under the same fermentation conditions suggesting better cell energy pool management in the absence of the ack-pta gene cluster in the engineered biocatalyst. If the first gene elimination step was used alone for spo0A gene replacement with two copies of synthetic formate dehydrogenase in recombinants with a shortened genome, mevalonate production was replaced with 76.5 mM formate production in a single step continuous CO2/H2 blend fermentation (p < 0.005) with cell duplication time almost nearing that of the wild strain.
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Kiriukhin M, Tyurin M. Mevalonate production by engineered acetogen biocatalyst during continuous fermentation of syngas or CO₂/H₂ blend. Bioprocess Biosyst Eng 2013; 37:245-60. [PMID: 23775000 DOI: 10.1007/s00449-013-0991-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Accepted: 05/31/2013] [Indexed: 11/30/2022]
Abstract
Naturally mevalonate-resistant acetogen Clostridium sp. MT1243 produced only 425 mM acetate during syngas fermentation. Using Clostridium sp. MT1243 we engineered biocatalyst selectively producing mevalonate from synthesis gas or CO₂/H₂ blend. Acetate production and spore formation were eliminated from Clostridium sp. MT1243 using Cre-lox66/lox71-system. Cell energy released via elimination of phosphotransacetylase, acetate kinase and early stage sporulation genes powered mevalonate accumulation in fermentation broth due to expression of synthetic thiolase, HMG-synthase, and HMG-reductase, three copies of each, integrated using Tn7-approach. Recombinants produced 145 mM mevalonate in five independent single-step fermentation runs 25 days each in five repeats using syngas blend 60% CO and 40% H₂ (v/v) (p < 0.005). Mevalonate production was 97 mM if only CO₂/H₂ blend was fed instead of syngas (p < 0.005). Mevalonate from CO₂/H₂ blend might serve as a commercial route to mitigate global warming in proportion to CO₂ fermentation scale worldwide.
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Affiliation(s)
- Michael Kiriukhin
- Syngas Biofuels Energy, Inc., P.O. Box 300819, Houston, TX, 77230, USA
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Contributions of environmental signals and conserved residues to the functions of carbon storage regulator A of Borrelia burgdorferi. Infect Immun 2013; 81:2972-85. [PMID: 23753623 DOI: 10.1128/iai.00494-13] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Carbon storage regulator A of Borrelia burgdorferi (CsrABb) contributes to vertebrate host-specific adaptation by modulating activation of the Rrp2-RpoN-RpoS pathway and is critical for infectivity. We hypothesized that the functions of CsrABb are dependent on environmental signals and on select residues. We analyzed the phenotype of csrABb deletion and site-specific mutants to determine the conserved and pathogen-specific attributes of CsrABb. Levels of phosphate acetyltransferase (Pta) involved in conversion of acetyl phosphate to acetyl-coenzyme A (acetyl-CoA) and posttranscriptionally regulated by CsrABb in the csrABb mutant were reduced from or similar to those in the control strains under unfed- or fed-tick conditions, respectively. Increased levels of supplemental acetate restored vertebrate host-responsive determinants in the csrABb mutant to parental levels, indicating that both the levels of CsrABb and the acetyl phosphate and acetyl-CoA balance contribute to the activation of the Rrp2-RpoN-RpoS pathway. Site-specific replacement of 8 key residues of CsrABb (8S) with alanines resulted in increased levels of CsrABb and reduced levels of Pta and acetyl-CoA, while levels of RpoS, BosR, and other members of rpoS regulon were elevated. Truncation of 7 amino acids at the C terminus of CsrABb (7D) resulted in reduced csrABb transcripts and posttranscriptionally reduced levels of FliW located upstream of CsrABb. Electrophoretic mobility shift assays revealed increased binding of 8S mutant protein to the CsrA binding box upstream of pta compared to the parental and 7D truncated protein. Two CsrABb binding sites were also identified upstream of fliW within the flgK coding sequence. These observations reveal conserved and unique functions of CsrABb that regulate adaptive gene expression in B. burgdorferi.
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Abstract
Borrelia 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. burgdorferi is known to be unique in metal utilization, and little is known of the role of biologically available metals in B. burgdorferi. Here, we identified two transition metal ions, manganese (Mn(2+)) and zinc (Zn(2+)), that influenced regulation of RpoS. The intracellular Mn(2+) 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 Mn(2+) repressed temperature-dependent induction of RpoS and OspC; this repression was overcome by an excess of Zn(2+). Conversely, a decrease of intracellular Mn(2+) by deletion of the Mn(2+) transporter gene, bmtA, resulted in elevated levels of RpoS and OspC. Mn(2+) affected RpoS through BosR, a Fur family homolog that is required for rpoS expression: elevated intracellular Mn(2+) levels greatly reduced the level of BosR protein but not the level of bosR mRNA. Thus, Mn(2+) and Zn(2+) 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 Mn(2+) and Zn(2+) play a critical role in regulation of virulence in bacteria.
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Miller CL, Karna SLR, Seshu J. Borrelia host adaptation Regulator (BadR) regulates rpoS to modulate host adaptation and virulence factors in Borrelia burgdorferi. Mol Microbiol 2013; 88:105-24. [PMID: 23387366 DOI: 10.1111/mmi.12171] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/02/2013] [Indexed: 11/27/2022]
Abstract
The RpoS transcription factor of Borrelia burgdorferi is a 'gatekeeper' because it activates genes required for spirochaetes to transition from tick to vertebrate hosts. However, it remains unknown how RpoS becomes repressed to allow the spirochaetes to transition back from the vertebrate host to the tick vector. Here we show that a putative carbohydrate-responsive regulatory protein, designated BadR (Borrelia host adaptation Regulator), is a transcriptional repressor of rpoS. BadR levels are elevated in B. burgdorferi cultures grown under in vitro conditions mimicking unfed-ticks and badR-deficient strains are defective for growth under these same conditions. Microarray and immunoblot analyses of badR-deficient strains showed upregulation of rpoS and other factors important for virulence in vertebrate hosts, as well as downregulation of putative tick-specific determinants (e.g. linear plasmid 28-4 genes). DNA-binding assays revealed BadR binds to upstream regions of rpoS. Site-directed mutations in BadR and the presence of phosphorylated sugars affected BadR's binding to the rpoS promoters. badR-deficient B. burgdorferi were unable to colonize mice. Several putative tick-specific targets have been identified. Our study identified a novel regulator, BadR, and provides a link between nutritional environmental cues utilized by spirochaetes to adaptation to disparate conditions found in the tick and vertebrate hosts.
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Affiliation(s)
- Christine L Miller
- South Texas Center for Emerging Infectious Diseases, Center for Excellence in Infection Genomics and Department of Biology, The University of Texas at San Antonio, San Antonio, Texas, USA
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Changes in bacterial growth rate govern expression of the Borrelia burgdorferi OspC and Erp infection-associated surface proteins. J Bacteriol 2012; 195:757-64. [PMID: 23222718 DOI: 10.1128/jb.01956-12] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The Lyme disease spirochete controls production of its OspC and Erp outer surface proteins, repressing protein synthesis during colonization of vector ticks but increasing expression when those ticks feed on vertebrate hosts. Early studies found that the synthesis of OspC and Erps can be stimulated in culture by shifting the temperature from 23°C to 34°C, leading to a hypothesis that Borrelia burgdorferi senses environmental temperature to determine its location in the tick-mammal infectious cycle. However, borreliae cultured at 34°C divide several times faster than do those cultured at 23°C. We developed methods that disassociate bacterial growth rate and temperature, allowing a separate evaluation of each factor's impacts on B. burgdorferi gene and protein expression. Altogether, the data support a new paradigm that B. burgdorferi actually responds to changes in its own replication rate, not temperature per se, as the impetus to increase the expression of the OspC and Erp infection-associated proteins.
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