1
|
Pětrošová H, Mikhael A, Culos S, Giraud-Gatineau A, Gomez AM, Sherman ME, Ernst RK, Cameron CE, Picardeau M, Goodlett DR. Lipid A structural diversity among members of the genus Leptospira. Front Microbiol 2023; 14:1181034. [PMID: 37303810 PMCID: PMC10248169 DOI: 10.3389/fmicb.2023.1181034] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 05/02/2023] [Indexed: 06/13/2023] Open
Abstract
Lipid A is the hydrophobic component of bacterial lipopolysaccharide and an activator of the host immune system. Bacteria modify their lipid A structure to adapt to the surrounding environment and, in some cases, to evade recognition by host immune cells. In this study, lipid A structural diversity within the Leptospira genus was explored. The individual Leptospira species have dramatically different pathogenic potential that ranges from non-infectious to life-threatening disease (leptospirosis). Ten distinct lipid A profiles, denoted L1-L10, were discovered across 31 Leptospira reference species, laying a foundation for lipid A-based molecular typing. Tandem MS analysis revealed structural features of Leptospira membrane lipids that might alter recognition of its lipid A by the host innate immune receptors. Results of this study will aid development of strategies to improve diagnosis and surveillance of leptospirosis, as well as guide functional studies on Leptospira lipid A activity.
Collapse
Affiliation(s)
- Helena Pětrošová
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
- University of Victoria Genome British Columbia Proteomics Center, University of Victoria, Victoria, BC, Canada
| | - Abanoub Mikhael
- University of Victoria Genome British Columbia Proteomics Center, University of Victoria, Victoria, BC, Canada
| | - Sophie Culos
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | | | - Alloysius M. Gomez
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Matthew E. Sherman
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, MD, United States
| | - Robert K. Ernst
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, MD, United States
| | - Caroline E. Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, United States
| | - Mathieu Picardeau
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Biology of Spirochetes Unit, Paris, France
| | - David R. Goodlett
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
- University of Victoria Genome British Columbia Proteomics Center, University of Victoria, Victoria, BC, Canada
| |
Collapse
|
2
|
Lauretti-Ferreira F, Teixeira AAR, Giordano RJ, da Silva JB, Abreu PAE, Barbosa AS, Akamatsu MA, Ho PL. Characterization of a virulence-modifying protein of Leptospira interrogans identified by shotgun phage display. Front Microbiol 2022; 13:1051698. [PMID: 36519163 PMCID: PMC9742253 DOI: 10.3389/fmicb.2022.1051698] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 11/08/2022] [Indexed: 09/02/2023] Open
Abstract
Pathogenic species of Leptospira are etiologic agents of leptospirosis, an emerging zoonotic disease of worldwide extent and endemic in tropical regions. The growing number of identified leptospiral species sheds light to their genetic diversity and unique virulence mechanisms, many of them still remain unknown. Toxins and adhesins are important virulence factors in several pathogens, constituting promising antigens for the development of vaccines with cross-protection and long-lasting effect against leptospirosis. For this aim, we used the shotgun phage display technique to unravel new proteins with adhesive properties. A shotgun library was constructed using fragmented genomic DNA from Leptospira interrogans serovar Copenhageni strain Fiocruz L1-130 and pG8SAET phagemid vector. Selection of phages bearing new possible cell-binding antigens was performed against VERO cells, using BRASIL biopanning methodology. Analysis of selected clones revealed the hypothetical protein LIC10778, a potentially exposed virulence factor that belongs to the virulence-modifying (VM) protein family (PF07598), composed of 13 members in the leptospiral strain Fiocruz L1-130. Prediction of LIC10778 tertiary structure indicates that the protein contains a cellular-binding domain (N-terminal portion) and an unknown domain of no assigned activity (C-terminal portion). The predicted N-terminal domain shared structural similarities with the cell-binding and internalization domain of toxins like Ricin and Abrin, as well as to the Community-Acquired Respiratory Distress Syndrome (CARDS) toxin in Mycoplasma pneumoniae. Interestingly, recombinant portions of the N-terminal region of LIC10778 protein showed binding to laminin, collagens I and IV, vitronectin, and plasma and cell fibronectins using overlay blotting technique, especially regarding the binding site identified by phage display. These data validate our preliminary phage display biopanning and support the predicted three-dimensional models of LIC10778 protein and other members of PF07598 protein family, confirming the identification of the N-terminal cell-binding domains that are similar to ricin-like toxins. Moreover, fluorescent fused proteins also confirmed that N-terminal region of LIC10778 is capable of binding to VERO and A549 cell lines, further highlighting its virulence role during host-pathogen interaction in leptospirosis probably mediated by its C-terminal domain. Indeed, recent results in the literature confirmed this assumption by demonstrating the cytotoxicity of a closely related PF07598 member.
Collapse
Affiliation(s)
- Fabiana Lauretti-Ferreira
- Bioindustrial Division, Butantan Institute, São Paulo, Brazil
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | | | - Ricardo José Giordano
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | | | | | | | | | - Paulo Lee Ho
- Bioindustrial Division, Butantan Institute, São Paulo, Brazil
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| |
Collapse
|
3
|
Chaurasia R, Salovey A, Guo X, Desir G, Vinetz JM. Vaccination With Leptospira interrogans PF07598 Gene Family-Encoded Virulence Modifying Proteins Protects Mice From Severe Leptospirosis and Reduces Bacterial Load in the Liver and Kidney. Front Cell Infect Microbiol 2022; 12:926994. [PMID: 35837473 PMCID: PMC9274288 DOI: 10.3389/fcimb.2022.926994] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 05/24/2022] [Indexed: 12/29/2022] Open
Abstract
The molecular and cellular pathogenesis of leptospirosis remains poorly understood. Based on comparative bacterial genomics data, we recently identified the hypothetical PF07598 gene family as encoding secreted exotoxins (VM proteins) that mediate cytotoxicity in vitro. To address whether VM proteins mediate in vivo leptospirosis pathogenesis, we tested the hypothesis that VM protein immunization of mice would protect against lethal challenge infection and reduce bacterial load in key target organs. C3H/HeJ mice were immunized with recombinant E. coli-produced, endotoxin-free, leptospiral VM proteins (derived from L. interrogans serovar Lai) in combination with the human-compatible adjuvant, glucopyranoside lipid A/squalene oil-in-water. Mice receiving full length recombinant VM proteins were protected from lethal challenge infection by L. interrogans serovar Canicola and had a 3-4 log10 reduction in bacterial load in the liver and kidney. These experiments show that immunization with recombinant VM proteins prevents leptospirosis clinical pathogenesis and leads to markedly reduced key target organ infection in this animal model. These data support the role of leptospiral VM proteins as virulence factors and suggest the possibility that a VM protein-based, serovar-independent, pan-leptospirosis vaccine may be feasible.
Collapse
Affiliation(s)
- Reetika Chaurasia
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, United States
| | - Aryeh Salovey
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, United States
| | - Xiaojia Guo
- Section of Nephrology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, United States
| | - Gary Desir
- Section of Nephrology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, United States
| | - Joseph M. Vinetz
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, United States
- *Correspondence: Joseph M. Vinetz,
| |
Collapse
|
4
|
Cagliero J, Vernel-Pauillac F, Murray G, Adler B, Matsui M, Werts C. Pathogenic Leptospires Limit Dendritic Cell Activation Through Avoidance of TLR4 and TRIF Signaling. Front Immunol 2022; 13:911778. [PMID: 35812397 PMCID: PMC9258186 DOI: 10.3389/fimmu.2022.911778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 05/26/2022] [Indexed: 11/13/2022] Open
Abstract
Leptospira interrogans is a bacterial species responsible for leptospirosis, a neglected worldwide zoonosis. Mice and rats are resistant and can become asymptomatic carriers, whereas humans and some other mammals may develop severe forms of leptospirosis. Uncommon among spirochetes, leptospires contain lipopolysaccharide (LPS) in their outer membrane. LPS is highly immunogenic and forms the basis for a large number of serovars. Vaccination with inactivated leptospires elicits a protective immunity, restricted to serovars with related LPS. This protection that lasts in mice, is not long lasting in humans and requires annual boosts. Leptospires are stealth pathogens that evade the complement system and some pattern recognition receptors from the Toll-like (TLR) and Nod-Like families, therefore limiting antibacterial defense. In macrophages, leptospires totally escape recognition by human TLR4, and escape the TRIF arm of the mouse TLR4 pathway. However, very little is known about the recognition and processing of leptospires by dendritic cells (DCs), although they are crucial cells linking innate and adaptive immunity. Here we tested the activation of primary DCs derived from human monocytes (MO-DCs) and mouse bone marrow (BM-DCs) 24h after stimulation with saprophytic or different pathogenic virulent or avirulent L. interrogans. We measured by flow cytometry the expression of DC-SIGN, a lectin involved in T-cell activation, co-stimulation molecules and MHC-II markers, and pro- and anti-inflammatory cytokines by ELISA. We found that exposure to leptospires, live or heat-killed, activated dendritic cells. However, pathogenic L. interrogans, especially from the Icterohaemorraghiae Verdun strain, triggered less marker upregulation and less cytokine production than the saprophytic Leptospira biflexa. In addition, we showed a better activation with avirulent leptospires, when compared to the virulent parental strains in murine BM-DCs. We did not observe this difference in human MO-DCs, suggesting a role for TLR4 in DC stimulation. Accordingly, using BM-DCs from transgenic deficient mice, we showed that virulent Icterohaemorraghiae and Manilae serovars dampened DC activation, at least partly, through the TLR4 and TRIF pathways. This work shows a novel bacterial immune evasion mechanism to limit DC activation and further illustrates the role of the leptospiral LPS as a virulence factor.
Collapse
Affiliation(s)
- Julie Cagliero
- Institut Pasteur de Nouvelle-Calédonie, member of the Pasteur Network, Immunity and Inflammation Group (GIMIN), Noumea, New Caledonia
- Institut Pasteur, Université de Paris, CNRS UMR6047, INSERM U1306, Unité de Biologie et Génétique de la Paroi bactérienne, F-75015 Paris, France
- Institut Pasteur de Nouvelle-Calédonie, member of the Pasteur Network, Leptospirosis Research and Expertise Unit, Noumea, New Caledonia
| | - Frédérique Vernel-Pauillac
- Institut Pasteur, Université de Paris, CNRS UMR6047, INSERM U1306, Unité de Biologie et Génétique de la Paroi bactérienne, F-75015 Paris, France
| | - Gerald Murray
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Australia
| | - Ben Adler
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Australia
| | - Mariko Matsui
- Institut Pasteur de Nouvelle-Calédonie, member of the Pasteur Network, Immunity and Inflammation Group (GIMIN), Noumea, New Caledonia
| | - Catherine Werts
- Institut Pasteur, Université de Paris, CNRS UMR6047, INSERM U1306, Unité de Biologie et Génétique de la Paroi bactérienne, F-75015 Paris, France
- *Correspondence: Catherine Werts,
| |
Collapse
|
5
|
Wickner S, Nguyen TLL, Genest O. The Bacterial Hsp90 Chaperone: Cellular Functions and Mechanism of Action. Annu Rev Microbiol 2021; 75:719-739. [PMID: 34375543 DOI: 10.1146/annurev-micro-032421-035644] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Heat shock protein 90 (Hsp90) is a molecular chaperone that folds and remodels proteins, thereby regulating the activity of numerous substrate proteins. Hsp90 is widely conserved across species and is essential in all eukaryotes and in some bacteria under stress conditions. To facilitate protein remodeling, bacterial Hsp90 collaborates with the Hsp70 molecular chaperone and its cochaperones. In contrast, the mechanism of protein remodeling performed by eukaryotic Hsp90 is more complex, involving more than 20 Hsp90 cochaperones in addition to Hsp70 and its cochaperones. In this review, we focus on recent progress toward understanding the basic mechanisms of bacterial Hsp90-mediated protein remodeling and the collaboration between Hsp90 and Hsp70. We describe the universally conserved structure and conformational dynamics of these chaperones and their interactions with one another and with client proteins. The physiological roles of Hsp90 in Escherichia coli and other bacteria are also discussed. We anticipate that the information gained from exploring the mechanism of the bacterial chaperone system will provide a framework for understanding the more complex eukaryotic Hsp90 system. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Collapse
Affiliation(s)
- Sue Wickner
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA;
| | - Thu-Lan Lily Nguyen
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA;
| | - Olivier Genest
- Aix-Marseille Université, CNRS, Laboratoire de Bioénergétique et Ingénierie des Protéines, Institut de Microbiologie de la Méditerranée, 13009 Marseille, France;
| |
Collapse
|
6
|
Vanithamani S, Akino Mercy CS, Kanagavel M, Sumaiya K, Bothammal P, Saranya P, Prasad M, Ponmurugan K, Muralitharan G, Al-Dhabi NA, Verma A, Vijayachari P, Natarajaseenivasan K. Biochemical analysis of leptospiral LPS explained the difference between pathogenic and non-pathogenic serogroups. Microb Pathog 2021; 152:104738. [PMID: 33529737 DOI: 10.1016/j.micpath.2021.104738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 01/02/2021] [Accepted: 01/07/2021] [Indexed: 10/22/2022]
Abstract
Lipopolysaccharide (LPS) is the major surface antigen of Leptospira. In this study, the genes involved in the LPS biosynthesis were analyzed and compared by bioinformatics tools. Also, the chemical composition analysis of leptospiral lipopolysaccharides (LPS) extracted from 5 pathogenic serovars like Autumnalis, Australis, Ballum, Grippotyphosa, Pomona, and the nonpathogenic serovar Andamana was performed. Methods used were Limulus amebocyte lysate assay (LAL), gas chromatography-mass spectrometry (GC-MS), fourier transform infrared spectroscopy (FT-IR), and nuclear magnetic resonance spectroscopy (NMR). LAL assay showed a significantly higher level of endotoxicity among pathogenic serovars (~0.490 EU/mL) than that of nonpathogenic Andamana (~0.102 EU/mL). FAMES analysis showed the presence of palmitic acid (C16:0), hydroxy lauric acid (3-OH-C12:0), and oleic acid (C18:0). Palmitoleic acid (C16: 1), and 3- hydroxy palmitate (3-OH-C16:0) was detected only in pathogenic serovars. In contrast myristoleic acid (C14:1) and stearic acid (C18:0) were present in Andamana. FTIR analysis revealed C-O-C stretch of esters, 3°ROH functional groups and carbohydrate vibration range were similar among pathogenic serovars. The NMR analysis reveals similarity for 6 deoxy sugars and methyl groups of Autumnalis, Australis, and Ballum. Further, the presence of palmitoleic acid and 3-hydroxy palmitate may be the significant pathogen-associated predisposing factor. This mediates high osmolarity glycerol (HOG) mediated stress response in leptospiral LPS mediated pathogenesis.
Collapse
Affiliation(s)
- Shanmugam Vanithamani
- Medical Microbiology Laboratory, Department of Microbiology, School of Life Sciences, Bharathidasan University, Tiruchirappalli, 620024, India
| | - Charles Solomon Akino Mercy
- Medical Microbiology Laboratory, Department of Microbiology, School of Life Sciences, Bharathidasan University, Tiruchirappalli, 620024, India
| | - Murugesan Kanagavel
- Medical Microbiology Laboratory, Department of Microbiology, School of Life Sciences, Bharathidasan University, Tiruchirappalli, 620024, India
| | - Krishnamoorthi Sumaiya
- Medical Microbiology Laboratory, Department of Microbiology, School of Life Sciences, Bharathidasan University, Tiruchirappalli, 620024, India
| | - Palanisamy Bothammal
- Medical Microbiology Laboratory, Department of Microbiology, School of Life Sciences, Bharathidasan University, Tiruchirappalli, 620024, India
| | - Perumal Saranya
- Medical Microbiology Laboratory, Department of Microbiology, School of Life Sciences, Bharathidasan University, Tiruchirappalli, 620024, India
| | - Muthu Prasad
- Medical Microbiology Laboratory, Department of Microbiology, School of Life Sciences, Bharathidasan University, Tiruchirappalli, 620024, India
| | - Karuppiah Ponmurugan
- Department of Botany & Microbiology, College of Science, King Saud University, P.O.Box 2455, Riyadh, 11451, Saudi Arabia
| | - Gangatharan Muralitharan
- Medical Microbiology Laboratory, Department of Microbiology, School of Life Sciences, Bharathidasan University, Tiruchirappalli, 620024, India
| | - Naif Abdullah Al-Dhabi
- Department of Botany & Microbiology, College of Science, King Saud University, P.O.Box 2455, Riyadh, 11451, Saudi Arabia
| | - Ashutosh Verma
- Lincoln Memorial University, College of Veterinary Medicine, Harrogate, TN, 37752, USA
| | - Paluru Vijayachari
- WHO Collaborating Centre for Diagnosis, Reference, Research and Training in Leptospirosis, Regional Medical Research Centre (ICMR), Port Blair, 744103, India
| | - Kalimuthusamy Natarajaseenivasan
- Medical Microbiology Laboratory, Department of Microbiology, School of Life Sciences, Bharathidasan University, Tiruchirappalli, 620024, India; Department of Neuroscience, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA.
| |
Collapse
|
7
|
Bonhomme D, Santecchia I, Vernel-Pauillac F, Caroff M, Germon P, Murray G, Adler B, Boneca IG, Werts C. Leptospiral LPS escapes mouse TLR4 internalization and TRIF‑associated antimicrobial responses through O antigen and associated lipoproteins. PLoS Pathog 2020; 16:e1008639. [PMID: 32790743 PMCID: PMC7447051 DOI: 10.1371/journal.ppat.1008639] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 08/25/2020] [Accepted: 07/07/2020] [Indexed: 12/12/2022] Open
Abstract
Leptospirosis is a worldwide re-emerging zoonosis caused by pathogenic Leptospira spp. All vertebrate species can be infected; humans are sensitive hosts whereas other species, such as rodents, may become long-term renal carrier reservoirs. Upon infection, innate immune responses are initiated by recognition of Microbial Associated Molecular Patterns (MAMPs) by Pattern Recognition Receptors (PRRs). Among MAMPs, the lipopolysaccharide (LPS) is recognized by the Toll-Like-Receptor 4 (TLR4) and activates both the MyD88-dependent pathway at the plasma membrane and the TRIF-dependent pathway after TLR4 internalization. We previously showed that leptospiral LPS is not recognized by the human-TLR4, whereas it signals through mouse-TLR4 (mTLR4), which mediates mouse resistance to acute leptospirosis. However, although resistant, mice are known to be chronically infected by leptospires. Interestingly, the leptospiral LPS has low endotoxicity in mouse cells and is an agonist of TLR2, the sensor for bacterial lipoproteins. Here, we investigated the signaling properties of the leptospiral LPS in mouse macrophages. Using confocal microscopy and flow cytometry, we showed that the LPS of L. interrogans did not induce internalization of mTLR4, unlike the LPS of Escherichia coli. Consequently, the LPS failed to induce the production of the TRIF-dependent nitric oxide and RANTES, both important antimicrobial responses. Using shorter LPS and LPS devoid of TLR2 activity, we further found this mTLR4-TRIF escape to be dependent on both the co-purifying lipoproteins and the full-length O antigen. Furthermore, our data suggest that the O antigen could alter the binding of the leptospiral LPS to the co-receptor CD14 that is essential for TLR4-TRIF activation. Overall, we describe here a novel leptospiral immune escape mechanism from mouse macrophages and hypothesize that the LPS altered signaling could contribute to the stealthiness and chronicity of the leptospires in mice. Leptospira interrogans is a bacterial pathogen, responsible for leptospirosis, a worldwide neglected reemerging disease. L. interrogans may cause an acute severe disease in humans, whereas rodents and other animals asymptomatically carry the leptospires in their kidneys. They can therefore excrete live bacteria in urine and contaminate the environment. Leptospires are stealth pathogens known to escape the innate immune defenses of their hosts. They are covered in lipopolysaccharide (LPS), a bacterial motif recognized in mammals through the Toll-like receptor 4 (TLR4), which triggers two different signaling pathways. We showed previously that pathogenic leptospires fully escape TLR4 recognition in humans. Here we focused on the LPS signaling in mice that are, although resistant to acute leptospirosis, chronically infected. We showed in mouse cells that the leptospiral LPS triggers only one arm of the TLR4 pathway and escapes the other, hence avoiding production of antimicrobial compounds. Removing the lipoproteins that always co-purify with the leptospiral LPS, or using shorter LPS, restores the stimulation of both pathways. This suggests a novel escape mechanism linked to the LPS and involving lipoproteins that could be instrumental for leptospires to escape the mouse defense and to allow for their chronic renal colonization.
Collapse
Affiliation(s)
- Delphine Bonhomme
- Institut Pasteur, Unité Biologie et Génétique de la Paroi Bactérienne, Paris, France; CNRS, UMR 2001 « Microbiologie intégrative et Moléculaire », Paris, France; INSERM, Equipe Avenir, Paris, France
- Université de Paris, Sorbonne Paris Cité, Paris, France
| | - Ignacio Santecchia
- Institut Pasteur, Unité Biologie et Génétique de la Paroi Bactérienne, Paris, France; CNRS, UMR 2001 « Microbiologie intégrative et Moléculaire », Paris, France; INSERM, Equipe Avenir, Paris, France
- Université de Paris, Sorbonne Paris Cité, Paris, France
| | - Frédérique Vernel-Pauillac
- Institut Pasteur, Unité Biologie et Génétique de la Paroi Bactérienne, Paris, France; CNRS, UMR 2001 « Microbiologie intégrative et Moléculaire », Paris, France; INSERM, Equipe Avenir, Paris, France
| | - Martine Caroff
- LPS-BioSciences, Université de Paris-Saclay, Orsay, France
| | - Pierre Germon
- INRAE, UMR ISP, Université François Rabelais de Tours, Nouzilly, France
| | - Gerald Murray
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Australia
| | - Ben Adler
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Australia
| | - Ivo G. Boneca
- Institut Pasteur, Unité Biologie et Génétique de la Paroi Bactérienne, Paris, France; CNRS, UMR 2001 « Microbiologie intégrative et Moléculaire », Paris, France; INSERM, Equipe Avenir, Paris, France
| | - Catherine Werts
- Institut Pasteur, Unité Biologie et Génétique de la Paroi Bactérienne, Paris, France; CNRS, UMR 2001 « Microbiologie intégrative et Moléculaire », Paris, France; INSERM, Equipe Avenir, Paris, France
- * E-mail:
| |
Collapse
|
8
|
Felix CR, Siedler BS, Barbosa LN, Timm GR, McFadden J, McBride AJA. An overview of human leptospirosis vaccine design and future perspectives. Expert Opin Drug Discov 2019; 15:179-188. [PMID: 31777290 DOI: 10.1080/17460441.2020.1694508] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Introduction: It's been 20 years since the first report of a recombinant vaccine that protected against leptospirosis. Since then, numerous recombinant vaccines have been evaluated; however, no recombinant vaccine candidate has advanced to clinical trials. With the ever-increasing burden of leptospirosis, there is an urgent need for a universal vaccine against leptospirosis.Areas covered: This review covers the most promising vaccine candidates that induced significant, reproducible, protection and how advances in the field of bioinformatics has led to the discovery of hundreds of novel protein targets. The authors also discuss the most recent findings regarding the innate immune response and host-pathogen interactions and their impact on the discovery of novel vaccine candidates. In addition, the authors have identified what they believe are the most challenging problems for the discovery and development of a universal vaccine and their potential solutions.Expert opinion: A universal vaccine for leptospirosis will likely only be achieved using a recombinant vaccine as the bacterins are of limited use due to the lack of a cross-protective immune response. Although there are hundreds of novel targets, due to the lack of immune correlates and the need for more research into the basic microbiology of Leptospira spp., a universal vaccine is 10-15 years away.
Collapse
Affiliation(s)
- Carolina R Felix
- Biotechnology Department, Centre for Technological Development, Federal University of Pelotas, Pelotas, Brazil
| | - Bianca S Siedler
- Biotechnology Department, Centre for Technological Development, Federal University of Pelotas, Pelotas, Brazil.,School of Biosciences and Medicine, Faculty of Health & Medical Sciences, University of Surrey, Guildford, UK
| | - Liana N Barbosa
- Biotechnology Department, Centre for Technological Development, Federal University of Pelotas, Pelotas, Brazil
| | - Gabriana R Timm
- Biotechnology Department, Centre for Technological Development, Federal University of Pelotas, Pelotas, Brazil
| | - Johnjoe McFadden
- School of Biosciences and Medicine, Faculty of Health & Medical Sciences, University of Surrey, Guildford, UK
| | - Alan J A McBride
- Biotechnology Department, Centre for Technological Development, Federal University of Pelotas, Pelotas, Brazil
| |
Collapse
|
9
|
Abstract
Until about 15 years ago, the molecular and cellular basis for pathogenesis in leptospirosis was virtually unknown. The determination of the first full genome sequence in 2003 was followed rapidly by other whole genome sequences, whose availability facilitated the development of transposon mutagenesis and then directed mutagenesis of pathogenic Leptospira spp. The combination of genomics, transcriptomics and mutant construction and characterisation has resulted in major progress in our understanding of the taxonomy and biology of Leptospira. The most recent advances are analysed and discussed in this chapter.
Collapse
Affiliation(s)
- Dieter Bulach
- Melbourne Bioinformatics, The University of Melbourne, Carlton, VIC, Australia
| | - Ben Adler
- Department of Microbiology, Monash University, Clayton, VIC, Australia.
| |
Collapse
|
10
|
Werts C. Interaction of Leptospira with the Innate Immune System. Curr Top Microbiol Immunol 2019; 415:163-187. [PMID: 29038956 DOI: 10.1007/82_2017_46] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Innate immunity encompasses immediate host responses that detect and respond to microbes. Besides recognition by the complement system (see the chapter by A. Barbosa, this volume), innate immunity concerns cellular responses. These are triggered through recognition of conserved microbial components (called MAMPs) by pattern recognition receptors (PRRs), leading, through secretion of cytokines, antimicrobial peptides, and immune mediators, to cellular recruitment and phagocytosis. Leptospira spp. are successful zoonotic pathogenic bacteria that obviously overcome the immune system of their hosts. The first part of this chapter summarizes what is known about leptospires recognition and interaction with phagocytes and other innate immune cells, and the second part describes specific interactions of leptospiral MAMPs with PRRs from the TLR and NLR families. On the one hand, pathogenic leptospires appear to escape macrophage and neutrophil phagocytosis. On the other hand, studies about PRR sensing of leptospires remain very limited, but suggest that pathogenic leptospires escape some of the PRRs in a host-specific manner, due to peculiar cell wall specificities or post-translational modifications that may impair their recognition. Further studies are necessary to clarify the mechanisms and consequences of leptospiral escape on phagocytic functions and hopefully give clues to potential therapeutic strategies aimed at restoring the defective activation of PRRs by pathogenic Leptospira spp.
Collapse
Affiliation(s)
- Catherine Werts
- Unité Biologie et Génétique de La Paroi Bactérienne, Institut Pasteur, Paris, France.
| |
Collapse
|
11
|
Abstract
This chapter covers the progress made in the Leptospira field since the application of mutagenesis techniques and how they have allowed the study of virulence factors and, more generally, the biology of Leptospira. The last decade has seen advances in our ability to perform molecular genetic analysis of Leptospira. Major achievements include the generation of large collections of mutant strains and the construction of replicative plasmids, enabling complementation of mutations. However, there are still no practical tools for routine genetic manipulation of pathogenic Leptospira strains, slowing down advances in pathogenesis research. This review summarizes the status of the molecular genetic toolbox for Leptospira species and highlights new challenges in the nascent field of Leptospira genetics.
Collapse
Affiliation(s)
- Mathieu Picardeau
- Biology of Spirochetes Unit, Institut Pasteur, 28 Rue Du Docteur Roux, 75724, Paris Cedex 15, France.
| |
Collapse
|
12
|
Thibeaux R, Iraola G, Ferrés I, Bierque E, Girault D, Soupé-Gilbert ME, Picardeau M, Goarant C. Deciphering the unexplored Leptospira diversity from soils uncovers genomic evolution to virulence. Microb Genom 2018; 4. [PMID: 29310748 PMCID: PMC5857368 DOI: 10.1099/mgen.0.000144] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Despite recent advances in our understanding of the genomics of members of the genus Leptospira, little is known on how virulence has emerged in this heterogeneous bacterial genus as well as on the lifestyle of pathogenic members of the genus Leptospira outside animal hosts. Here, we isolated 12 novel species of the genus Leptospira from tropical soils, significantly increasing the number of known species to 35 and finding evidence of highly unexplored biodiversity in the genus. Extended comparative phylogenomics and pan-genome analyses at the genus level by incorporating 26 novel genomes, revealed that, the traditional leptospiral ‘pathogens’ cluster, as defined by their phylogenetic position, can be split in two groups with distinct virulence potential and accessory gene patterns. These genomic distinctions are strongly linked to the ability to cause or not severe infections in animal models and humans. Our results not only provide new insights into virulence evolution in the members of the genus Leptospira, but also lay the foundations for refining the classification of the pathogenic species.
Collapse
Affiliation(s)
- Roman Thibeaux
- 1Institut Pasteur in New Caledonia, Institut Pasteur International Network, Leptospirosis Research and Expertise Unit, Noumea, New Caledonia
| | | | - Ignacio Ferrés
- 2Institut Pasteur Montevideo, Bioinformatics Unit, Uruguay
| | - Emilie Bierque
- 1Institut Pasteur in New Caledonia, Institut Pasteur International Network, Leptospirosis Research and Expertise Unit, Noumea, New Caledonia
| | - Dominique Girault
- 1Institut Pasteur in New Caledonia, Institut Pasteur International Network, Leptospirosis Research and Expertise Unit, Noumea, New Caledonia
| | - Marie-Estelle Soupé-Gilbert
- 1Institut Pasteur in New Caledonia, Institut Pasteur International Network, Leptospirosis Research and Expertise Unit, Noumea, New Caledonia
| | - Mathieu Picardeau
- 3Institut Pasteur, Unité de Biologie des Spirochètes, 28 rue du docteur Roux, 75724 Paris Cedex 15, France
| | - Cyrille Goarant
- 1Institut Pasteur in New Caledonia, Institut Pasteur International Network, Leptospirosis Research and Expertise Unit, Noumea, New Caledonia
| |
Collapse
|
13
|
Lourdault K, Matsunaga J, Evangelista KV, Haake DA. High-throughput Parallel Sequencing to Measure Fitness of Leptospira interrogans Transposon Insertion Mutants During Golden Syrian Hamster Infection. J Vis Exp 2017. [PMID: 29286406 DOI: 10.3791/56442] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In this manuscript, we describe a transposon sequencing (Tn-Seq) technique to identify and quantify Leptospira interrogans mutants altered in fitness during infection of Golden Syrian hamsters. Tn-Seq combines random transposon mutagenesis with the power of high-throughput sequencing technology. Animals are challenged with a pool of transposon mutants (input pool), followed by harvesting of blood and tissues a few days later to identify and quantify the number of mutants in each organ (output pools). The output pools are compared to the input pool to evaluate the in vivo fitness of each mutant. This approach enables screening of a large pool of mutants in a limited number of animals. With minor modifications, this protocol can be performed with any animal model of leptospirosis, reservoir host models such as rats and acute infection models such as hamsters, as well as in vitro studies. Tn-Seq provides a powerful tool to screen for mutants with in vivo and in vitro fitness defects.
Collapse
Affiliation(s)
- Kristel Lourdault
- Veterans Affairs Greater Los Angeles Healthcare System; Departments of Medicine, David Geffen School of Medicine at University of California Los Angeles;
| | - James Matsunaga
- Veterans Affairs Greater Los Angeles Healthcare System; Departments of Medicine, David Geffen School of Medicine at University of California Los Angeles
| | - Karen V Evangelista
- Veterans Affairs Greater Los Angeles Healthcare System; Departments of Medicine, David Geffen School of Medicine at University of California Los Angeles
| | - David A Haake
- Veterans Affairs Greater Los Angeles Healthcare System; Departments of Medicine, David Geffen School of Medicine at University of California Los Angeles; Departments of Urology, David Geffen School of Medicine at University of California Los Angeles; Departments of Microbiology, Immunology, and Molecular Genetics, University of California Los Angeles
| |
Collapse
|
14
|
Sato H, Coburn J. Leptospira interrogans causes quantitative and morphological disturbances in adherens junctions and other biological groups of proteins in human endothelial cells. PLoS Negl Trop Dis 2017; 11:e0005830. [PMID: 28750011 PMCID: PMC5549773 DOI: 10.1371/journal.pntd.0005830] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 08/08/2017] [Accepted: 07/24/2017] [Indexed: 12/21/2022] Open
Abstract
Pathogenic Leptospira transmits from animals to humans, causing the zoonotic life-threatening infection called leptospirosis. This infection is reported worldwide with higher risk in tropical regions. Symptoms of leptospirosis range from mild illness to severe illness such as liver damage, kidney failure, respiratory distress, meningitis, and fatal hemorrhagic disease. Invasive species of Leptospira rapidly disseminate to multiple tissues where this bacterium damages host endothelial cells, increasing vascular permeability. Despite the burden in humans and animals, the pathogenic mechanisms of Leptospira infection remain to be elucidated. The pathogenic leptospires adhere to endothelial cells and permeabilize endothelial barriers in vivo and in vitro. In this study, human endothelial cells were infected with the pathogenic L. interrogans serovar Copenhageni or the saprophyte L. biflexa serovar Patoc to investigate morphological changes and other distinctive phenotypes of host cell proteins by fluorescence microscopy. Among those analyzed, 17 proteins from five biological classes demonstrated distinctive phenotypes in morphology and/or signal intensity upon infection with Leptospira. The affected biological groups include: 1) extracellular matrix, 2) intercellular adhesion molecules and cell surface receptors, 3) intracellular proteins, 4) cell-cell junction proteins, and 5) a cytoskeletal protein. Infection with the pathogenic strain most profoundly disturbed the biological structures of adherens junctions (VE-cadherin and catenins) and actin filaments. Our data illuminate morphological disruptions and reduced signals of cell-cell junction proteins and filamentous actin in L. interrogans-infected endothelial cells. In addition, Leptospira infection, regardless of pathogenic status, influenced other host proteins belonging to multiple biological classes. Our data suggest that this zoonotic agent may damage endothelial cells via multiple cascades or pathways including endothelial barrier damage and inflammation, potentially leading to vascular hyperpermeability and severe illness in vivo. This work provides new insights into the pathophysiological mechanisms of Leptospira infection.
Collapse
Affiliation(s)
- Hiromi Sato
- Center for Infectious Disease Research, Department of Medicine, Division of Infectious Diseases, Medical College of Wisconsin, Milwaukee, WI, United States of America
| | - Jenifer Coburn
- Center for Infectious Disease Research, Department of Medicine, Division of Infectious Diseases, Medical College of Wisconsin, Milwaukee, WI, United States of America
- * E-mail:
| |
Collapse
|
15
|
Xia B, Sun L, Fan X, Xiao H, Zhu Y, Qin J, Cai C, Zhao W, Chang YF, Zhang Y, Guo X, He P. A new model of self-resolving leptospirosis in mice infected with a strain of Leptospira interrogans serovar Autumnalis harboring LPS signaling only through TLR4. Emerg Microbes Infect 2017; 6:e36. [PMID: 28536433 PMCID: PMC5520481 DOI: 10.1038/emi.2017.16] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 01/19/2017] [Accepted: 02/13/2017] [Indexed: 12/14/2022]
Abstract
Leptospirosis is an emerging worldwide zoonosis caused by pathogenic Leptospira spp. Our understanding of leptospirosis pathogenesis and host immune response remains limited, while mechanistic studies are hindered by a lack of proper animal models and immunological reagents. Here we established a murine model of acute and self-resolving leptospirosis by infecting 10-week-old C57BL/6 mice with Leptospira interrogans serovar Autumnalis strain 56606v, with characteristic manifestations including jaundice as well as subcutaneous and pulmonary bleeding, but no kidney lesions. We also verified that the lipopolysaccharide (LPS) of strain 56606v signaled through a TLR4-dependent pathway in murine bone marrow-derived macrophages (BMDMs), rather than the previously reported TLR2. In addition, upon infection with Leptospira strain 56606v, TLR4−/− C57BL/6 mice presented more severe jaundice and liver injury as well as higher bacterial loads than WT mice but milder pulmonary hemorrhaging. Molecular studies showed that leptospirosis-related bleeding coincides with the temporal kinetics of iNOS production, while jaundice and liver injury are probably due to insufficiently controlled bacterial loads in the liver. These results suggested that TLR4 is essential in mediating host leptospiral clearance and, to some extent, is associated with pulmonary and subcutaneous hemorrhage, probably through downstream inflammatory mediators, iNOS in particular. Overall, our murine model using immunocompetent mice might facilitate future studies into the pathogenesis of jaundice and bleeding in leptospirosis. Meanwhile, our study suggests the prospect of combining antibiotics and immunosuppressants in the treatment of severe leptospirosis presenting with pulmonary hemorrhage.
Collapse
Affiliation(s)
- Bili Xia
- Department of Microbiology and Immunology, Institutes of Medical Science, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.,Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
| | - Le Sun
- Department of Microbiology and Immunology, Institutes of Medical Science, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xia Fan
- Department of Microbiology and Immunology, Institutes of Medical Science, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Haihan Xiao
- Department of Microbiology and Immunology, Institutes of Medical Science, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yongzhang Zhu
- Department of Microbiology and Immunology, Institutes of Medical Science, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jinhong Qin
- Department of Microbiology and Immunology, Institutes of Medical Science, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Chengsong Cai
- Department of Laboratory Medicine, Affiliated Hospital of Hangzhou Normal University, Hangzhou 311121, Zhejiang Province, China
| | - Wei Zhao
- Department of Microbiology and Immunology, Institutes of Medical Science, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yung-Fu Chang
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Yan Zhang
- Department of Microbiology and Immunology, Institutes of Medical Science, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xiaokui Guo
- Department of Microbiology and Immunology, Institutes of Medical Science, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Ping He
- Department of Microbiology and Immunology, Institutes of Medical Science, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| |
Collapse
|
16
|
Gomes-Solecki M, Santecchia I, Werts C. Animal Models of Leptospirosis: Of Mice and Hamsters. Front Immunol 2017; 8:58. [PMID: 28270811 PMCID: PMC5318464 DOI: 10.3389/fimmu.2017.00058] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 01/16/2017] [Indexed: 01/27/2023] Open
Abstract
Pathogenic Leptospira sp. are spirochetal bacteria responsible for leptospirosis, an emerging worldwide zoonosis. These spirochetes are very successful pathogens that infect a wide range of hosts such as fish, reptiles, birds, marsupials, and mammals. Transmission occurs when chronically infected animals excrete live bacteria in their urine, contaminating the environment. Leptospira sp. enter their hosts through damaged skin and mucosa. Chronically infected rats and mice are asymptomatic and are considered as important reservoirs of the disease. Infected humans may develop either a flu-like, usually mild illness with or without chronic asymptotic renal colonization, or a severe acute disease with kidney, liver, and heart failure, potentially leading to death. Leptospirosis is an economic burden on society due to health-care costs related to elevated morbidity of humans and loss of animals of agricultural interest. There are no effective vaccines against leptospirosis. Leptospira sp. are difficult to genetically manipulate which delays the pace of research progress. In this review, we discuss in an historical perspective how animal models have contributed to further our knowledge of leptospirosis. Hamsters, guinea pigs, and gerbils have been instrumental to study the pathophysiology of acute lethal leptospirosis and the Leptospira sp. genes involved in virulence. Chronic renal colonization has been mostly studied using experimentally infected rats. A special emphasis will be placed on mouse models, long thought to be irrelevant since they survive lethal infection. However, mice have recently been shown to be good models of sublethal infection leading to chronic colonization. Furthermore, congenic and transgenic mice have proven essential to study how innate immune cells interact with the pathogen and to understand the role of the toll-like receptor 4, which is important to control Leptospira sp. load and disease. The use of inbred and transgenic mouse models opens up the field to the comprehensive study of immune responses to Leptospira sp. infection and subsequent pathophysiology of inflammation. It also allows for testing of drugs and vaccines in a biological system that can avail of a wealth of molecular tools that enable understanding of the mechanisms of action of protective vaccines.
Collapse
Affiliation(s)
- Maria Gomes-Solecki
- Department of Microbiology, Immunology and Biochemistry, The University of Tennessee Health Science Center , Memphis, TN , USA
| | - Ignacio Santecchia
- Institut Pasteur, Unité Biologie et Génétique de la Paroi Bactérienne, Paris, France; INSERM, équipe Avenir, Paris, France
| | - Catherine Werts
- Institut Pasteur, Unité Biologie et Génétique de la Paroi Bactérienne, Paris, France; INSERM, équipe Avenir, Paris, France
| |
Collapse
|
17
|
Lourdault K, Matsunaga J, Haake DA. High-Throughput Parallel Sequencing to Measure Fitness of Leptospira interrogans Transposon Insertion Mutants during Acute Infection. PLoS Negl Trop Dis 2016; 10:e0005117. [PMID: 27824878 PMCID: PMC5100919 DOI: 10.1371/journal.pntd.0005117] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 10/18/2016] [Indexed: 12/19/2022] Open
Abstract
Pathogenic species of Leptospira are the causative agents of leptospirosis, a zoonotic disease that causes mortality and morbidity worldwide. The understanding of the virulence mechanisms of Leptospira spp is still at an early stage due to the limited number of genetic tools available for this microorganism. The development of random transposon mutagenesis in pathogenic strains a decade ago has contributed to the identification of several virulence factors. In this study, we used the transposon sequencing (Tn-Seq) technique, which combines transposon mutagenesis with massive parallel sequencing, to study the in vivo fitness of a pool of Leptospira interrogans mutants. We infected hamsters with a pool of 42 mutants (input pool), which included control mutants with insertions in four genes previously analyzed by virulence testing (loa22, ligB, flaA1, and lic20111) and 23 mutants with disrupted signal transduction genes. We quantified the mutants in different tissues (blood, kidney and liver) at 4 days post-challenge by high-throughput sequencing and compared the frequencies of mutants recovered from tissues to their frequencies in the input pool. Control mutants that were less fit in the Tn-Seq experiment were attenuated for virulence when tested separately in the hamster model of lethal leptospirosis. Control mutants with unaltered fitness were as virulent as the wild-type strain. We identified two mutants with the transposon inserted in the same putative adenylate/guanylate cyclase gene (lic12327) that had reduced in vivo fitness in blood, kidney and liver. Both lic12327 mutants were attenuated for virulence when tested individually in hamsters. Growth of the control mutants and lic12327 mutants in culture medium were similar to that of the wild-type strain. These results demonstrate the feasibility of screening large pools of L. interrogans transposon mutants for those with altered fitness, and potentially attenuated virulence, by transposon sequencing.
Collapse
Affiliation(s)
- Kristel Lourdault
- Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
- Departments of Medicine, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, United States of America
| | - James Matsunaga
- Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
- Departments of Medicine, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, United States of America
| | - David A. Haake
- Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
- Departments of Medicine, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, United States of America
- Departments of Urology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, United States of America
- Departments of Microbiology, Immunology, and Molecular Genetics, University of California Los Angeles, Los Angeles, California, United States of America
| |
Collapse
|
18
|
Schons-Fonseca L, da Silva JB, Milanez JS, Domingos RH, Smith JL, Nakaya HI, Grossman AD, Ho PL, da Costa RMA. Analysis of LexA binding sites and transcriptomics in response to genotoxic stress in Leptospira interrogans. Nucleic Acids Res 2016; 44:1179-91. [PMID: 26762976 PMCID: PMC4756842 DOI: 10.1093/nar/gkv1536] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 12/15/2015] [Accepted: 12/25/2015] [Indexed: 11/13/2022] Open
Abstract
We determined the effects of DNA damage caused by ultraviolet radiation on gene expression in Leptospira interrogans using DNA microarrays. These data were integrated with DNA binding in vivo of LexA1, a regulator of the DNA damage response, assessed by chromatin immunoprecipitation and massively parallel DNA sequencing (ChIP-seq). In response to DNA damage, Leptospira induced expression of genes involved in DNA metabolism, in mobile genetic elements and defective prophages. The DNA repair genes involved in removal of photo-damage (e.g. nucleotide excision repair uvrABC, recombinases recBCD and resolvases ruvABC) were not induced. Genes involved in various metabolic pathways were down regulated, including genes involved in cell growth, RNA metabolism and the tricarboxylic acid cycle. From ChIP-seq data, we observed 24 LexA1 binding sites located throughout chromosome 1 and one binding site in chromosome 2. Expression of many, but not all, genes near those sites was increased following DNA damage. Binding sites were found as far as 550 bp upstream from the start codon, or 1 kb into the coding sequence. Our findings indicate that there is a shift in gene expression following DNA damage that represses genes involved in cell growth and virulence, and induces genes involved in mutagenesis and recombination.
Collapse
Affiliation(s)
- Luciane Schons-Fonseca
- Centro de Biotecnologia, Instituto Butantan, São Paulo, São Paulo 05503-900, Brazil Instituto de Química, Universidade de São Paulo, São Paulo, São Paulo 05508-000, Brazil Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, MA 02139, USA
| | - Josefa B da Silva
- Centro de Biotecnologia, Instituto Butantan, São Paulo, São Paulo 05503-900, Brazil
| | - Juliana S Milanez
- Centro de Biotecnologia, Instituto Butantan, São Paulo, São Paulo 05503-900, Brazil Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, São Paulo 05508-000, Brazil
| | - Renan H Domingos
- Centro de Biotecnologia, Instituto Butantan, São Paulo, São Paulo 05503-900, Brazil
| | - Janet L Smith
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, MA 02139, USA
| | - Helder I Nakaya
- Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, São Paulo 05508-000, Brazil
| | - Alan D Grossman
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, MA 02139, USA
| | - Paulo L Ho
- Centro de Biotecnologia, Instituto Butantan, São Paulo, São Paulo 05503-900, Brazil
| | - Renata M A da Costa
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, São Paulo 09210580, Brazil
| |
Collapse
|
19
|
Eshghi A, Henderson J, Trent MS, Picardeau M. Leptospira interrogans lpxD Homologue Is Required for Thermal Acclimatization and Virulence. Infect Immun 2015; 83:4314-21. [PMID: 26283339 PMCID: PMC4598399 DOI: 10.1128/iai.00897-15] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 08/13/2015] [Indexed: 12/20/2022] Open
Abstract
Leptospirosis is an emerging disease with an annual occurrence of over 1 million human cases worldwide. Pathogenic Leptospira bacteria are maintained in zoonotic cycles involving a diverse array of mammals, with the capacity to survive outside the host in aquatic environments. Survival in the diverse environments encountered by Leptospira likely requires various adaptive mechanisms. Little is known about Leptospira outer membrane modification systems, which may contribute to the capacity of these bacteria to successfully inhabit and colonize diverse environments and animal hosts. Leptospira bacteria carry two genes annotated as UDP-3-O-[3-hydroxymyristoyl] glucosamine N-acyltransferase genes (la0512 and la4326 [lpxD1 and lpxD2]) that in other bacteria are involved in the early steps of biosynthesis of lipid A, the membrane lipid anchor of lipopolysaccharide. Inactivation of only one of these genes, la0512/lpxD1, imparted sensitivity to the host physiological temperature (37°C) and rendered the bacteria avirulent in an animal infection model. Polymyxin B sensitivity assays revealed compromised outer membrane integrity in the lpxD1 mutant at host physiological temperature, but structural analysis of lipid A in the mutant revealed only minor changes in the lipid A moiety compared to that found in the wild-type strain. In accordance with this, an in trans complementation restored the phenotypes to a level comparable to that of the wild-type strain. These results suggest that the gene annotated as lpxD1 in Leptospira interrogans plays an important role in temperature adaptation and virulence in the animal infection model.
Collapse
Affiliation(s)
- Azad Eshghi
- Institut Pasteur, Biology of Spirochetes Unit, Paris, France
| | - Jeremy Henderson
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, USA
| | - M Stephen Trent
- Department of Infectious Disease, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | | |
Collapse
|
20
|
Patra KP, Choudhury B, Matthias MM, Baga S, Bandyopadhya K, Vinetz JM. Comparative analysis of lipopolysaccharides of pathogenic and intermediately pathogenic Leptospira species. BMC Microbiol 2015; 15:244. [PMID: 26518696 PMCID: PMC4628369 DOI: 10.1186/s12866-015-0581-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 10/23/2015] [Indexed: 12/31/2022] Open
Abstract
Background Lipopolysaccharides (LPS) are complex, amphipathic biomolecules that constitute the major surface component of Gram-negative bacteria. Leptospira, unlike other human-pathogenic spirochetes, produce LPS, which is fundamental to the taxonomy of the genus, involved in host-adaption and also the target of diagnostic antibodies. Despite its significance, little is known of Leptospira LPS composition and carbohydrate structure among different serovars. Results LPS from Leptospira interrogans serovar Copenhageni strain L1-130, a pathogenic species, and L. licerasiae serovar Varillal strain VAR 010, an intermediately pathogenic species, were studied. LPS prepared from aqueous and phenol phases were analyzed separately. L. interrogans serovar Copenhageni has additional sugars not found in L. licerasiae serovar Varillal, including fucose (2.7 %), a high amount of GlcNAc (12.3 %), and two different types of dideoxy HexNAc. SDS-PAGE indicated that L. interrogans serovar Copenhageni LPS had a far higher molecular weight and complexity than that of L. licerasiae serovar Varillal. Chemical composition showed that L. interrogans serovar Copenhageni LPS has an extended O-antigenic polysaccharide consisting of sugars, not present in L. licerasiae serovar Varillal. Arabinose, xylose, mannose, galactose and L-glycero-D-mannoheptose were detected in both the species. Fatty acid analysis by gas chromatography–mass spectrometry (GC-MS) showed the presence of hydroxypalmitate (3-OH-C16:0) only in L. interrogans serovar Copenhageni. Negative staining electron microscopic examination of LPS showed different filamentous morphologies in L. interrogans serovar Copenhageni vs. L. licerasiae serovar Varillal. Conclusions This comparative biochemical analysis of pathogenic and intermediately pathogenic Leptospira LPS reveals important carbohydrate and lipid differences that underlie future work in understanding the mechanisms of host-adaptation, pathogenicity and vaccine development in leptospirosis.
Collapse
Affiliation(s)
- Kailash P Patra
- Division of Infectious Diseases, Department of Medicine, Biomedical Research Facility, University of California San Diego, 9500 Gilman Drive, BRF 2, Room 5220, La Jolla, 92093-0760, California, USA.
| | - Biswa Choudhury
- Glycotechnology Core Resources, University of California San Diego, 9500 Gilman Drive, BRF 2, Room 4243, La Jolla, 92093-0687, California, USA.
| | - Michael M Matthias
- Division of Infectious Diseases, Department of Medicine, Biomedical Research Facility, University of California San Diego, 9500 Gilman Drive, BRF 2, Room 5220, La Jolla, 92093-0760, California, USA.
| | - Sheyenne Baga
- Division of Infectious Diseases, Department of Medicine, Biomedical Research Facility, University of California San Diego, 9500 Gilman Drive, BRF 2, Room 5220, La Jolla, 92093-0760, California, USA.
| | - Keya Bandyopadhya
- Glycotechnology Core Resources, University of California San Diego, 9500 Gilman Drive, BRF 2, Room 4243, La Jolla, 92093-0687, California, USA.
| | - Joseph M Vinetz
- Division of Infectious Diseases, Department of Medicine, Biomedical Research Facility, University of California San Diego, 9500 Gilman Drive, BRF 2, Room 5220, La Jolla, 92093-0760, California, USA.
| |
Collapse
|
21
|
Mouse model for sublethal Leptospira interrogans infection. Infect Immun 2015; 83:4693-700. [PMID: 26416909 DOI: 10.1128/iai.01115-15] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 09/15/2015] [Indexed: 01/24/2023] Open
Abstract
Although Leptospira can infect a wide range of mammalian species, most studies have been conducted in golden Syrian hamsters, a species particularly sensitive to acute disease. Chronic disease has been well characterized in the rat, one of the natural reservoir hosts. Studies in another asymptomatic reservoir host, the mouse, have occasionally been done and have limited infection to mice younger than 6 weeks of age. We analyzed the outcome of sublethal infection of C3H/HeJ mice older than age 10 weeks with Leptospira interrogans serovar Copenhageni. Infection led to bloodstream dissemination of Leptospira, which was followed by urinary shedding, body weight loss, hypothermia, and colonization of the kidney by live spirochetes 2 weeks after infection. In addition, Leptospira dissemination triggered inflammation in the kidney but not in the liver or lung, as determined by increased levels of mRNA transcripts for the keratinocyte-derived chemokine, RANTES, macrophage inflammatory protein 2, tumor necrosis factor alpha, interleukin-1β, inducible nitric oxide synthase, interleukin-6, and gamma interferon in kidney tissue. The acquired humoral response to Leptospira infection led to the production of IgG mainly of the IgG1 subtype. Flow cytometric analysis of splenocytes from infected mice revealed that cellular expansion was primarily due to an increase in the levels of CD4(+) and double-negative T cells (not CD8(+) cells) and that CD4(+) T cells acquired a CD44(high) CD62L(low) effector phenotype not accompanied by increases in memory T cells. A mouse model for sublethal Leptospira infection allows understanding of the bacterial and host factors that lead to immune evasion, which can result in acute or chronic disease or resistance to infection (protection).
Collapse
|
22
|
Koizumi N, Izumiya H, Mu JJ, Arent Z, Okano S, Nakajima C, Suzuki Y, Mizutani Muto M, Tanikawa T, Taylor KR, Komatsu N, Yoshimatsu K, Thi Thu Ha H, Ohnishi M. Multiple-locus variable-number tandem repeat analysis of Leptospira interrogans and Leptospira borgpetersenii isolated from small feral and wild mammals in East Asia. INFECTION GENETICS AND EVOLUTION 2015; 36:434-440. [PMID: 26296603 DOI: 10.1016/j.meegid.2015.08.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 08/07/2015] [Accepted: 08/08/2015] [Indexed: 11/19/2022]
Abstract
Leptospira spp. are the causative agents of a worldwide zoonosis, leptospirosis, maintained by various mammals. Each Leptospira serovar is frequently associated with a particular maintenance host, and recently, Leptospira genotype-host association has also been suggested to limit serovars to restricted areas. We investigated the molecular characteristics of L. interrogans and L. borgpetersenii which were isolated from small feral and wild animals in four East Asian states using multiple-locus variable-number tandem repeat analysis (MLVA). MLVA using 11 loci was performed on 110 L. interrogans serogroups from Japan (79 strains of 5 serogroups from 3 animal species), Philippines (21; 3; 2), Taiwan (7; 2; 3), and Vietnam (3; 1; 1). A MLVA method using 4 loci for L. borgpetersenii was established and performed on 52 isolates from Japan (26; 3; 7), Philippines (13; 1; 2), and Taiwan (13; 1; 3). In L. interrogans, serogroups Autumnalis and Hebdomadis appeared more genetically diverse than serogroups Bataviae, Grippotyphosa, Icterohaemorrhagiae, Pomona, or Pyrogenes. The former serogroup strains with the exception of one Hebdomadis strain were isolated from Apodemus speciosus while all the latter serogroup strains with the exception of Grippotyphosa were isolated from Rattus norvegicus. L. borgpetersenii was isolated from at least 11 animal species while L. interrogans was isolated from five species, which might suggest a wider host range for L. borgpetersenii. Broad host preference in a single genotype was also observed, which colonized not only different species of the same genera but also multiple animal genera. This study demonstrates that there may be variability in the range of genetic diversity among different Leptospira serogroups, which may be attributed to maintenance host animals and environmental factors.
Collapse
Affiliation(s)
- Nobuo Koizumi
- Department of Bacteriology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
| | - Hidemasa Izumiya
- Department of Bacteriology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Jung-Jung Mu
- Bacterial Enteric and Emerging Diseases Laboratory, Center for Research, Diagnostics and Vaccine Development, Centers for Disease Control, Taiwan, No. 161 Kun-Yang Street, Taipei, 11561, Taiwan
| | - Zbigniew Arent
- OIE Leptospirosis Reference Laboratory, Veterinary Sciences Division, Agri-Food and Biosciences Institute, Stoney Road, Belfast BT4 3 SD, United Kingdom
| | - Shou Okano
- Department of Biological Sciences, Okinawa Prefectural Institute of Health and Environment, 2085 Ozato, Ozato, Nanjo-shi, Okinawa 901-1202, Japan
| | - Chie Nakajima
- Division of Bioresources, Hokkaido University Research Center for Zoonosis Control, Kita-20, Nishi-10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan
| | - Yasuhiko Suzuki
- Division of Bioresources, Hokkaido University Research Center for Zoonosis Control, Kita-20, Nishi-10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan
| | - Maki Mizutani Muto
- Department of Bacteriology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Tsutomu Tanikawa
- Ikari Corporation, 579 Chibatera-machi, Chuo-ku, Chiba, Chiba 260-0844, Japan
| | - Kyle R Taylor
- Laboratory of Wildlife Biology and Medicine, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18, Nishi-9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan
| | - Noriyuki Komatsu
- Civil International Corporation, 1-19-4 Imado, Taito-ku, Tokyo 111-0024, Japan
| | - Kumiko Yoshimatsu
- Department of Microbiology, Graduate School of Medicine, Hokkaido University, Kita-15, Nishi-7, Kita-ku, Sapporo, Hokkaido 060-8638, Japan
| | - Hoang Thi Thu Ha
- Bacteriology Department, National Institute of Hygiene and Epidemiology, Hanoi 10000, Vietnam
| | - Makoto Ohnishi
- Department of Bacteriology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| |
Collapse
|
23
|
Eshghi A, Pappalardo E, Hester S, Thomas B, Pretre G, Picardeau M. Pathogenic Leptospira interrogans exoproteins are primarily involved in heterotrophic processes. Infect Immun 2015; 83:3061-73. [PMID: 25987703 PMCID: PMC4496612 DOI: 10.1128/iai.00427-15] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 05/11/2015] [Indexed: 12/19/2022] Open
Abstract
Leptospirosis is a life-threatening and emerging zoonotic disease with a worldwide annual occurrence of more than 1 million cases. Leptospirosis is caused by spirochetes belonging to the genus Leptospira. The mechanisms of disease manifestation in the host remain elusive, and the roles of leptospiral exoproteins in these processes have yet to be determined. Our aim in this study was to assess the composition and quantity of exoproteins of pathogenic Leptospira interrogans and to construe how these proteins contribute to disease pathogenesis. Label-free quantitative mass spectrometry of proteins obtained from Leptospira spirochetes cultured in vitro under conditions mimicking infection identified 325 exoproteins. The majority of these proteins are conserved in the nonpathogenic species Leptospira biflexa, and proteins involved in metabolism and energy-generating functions were overrepresented and displayed the highest relative abundance in culture supernatants. Conversely, proteins of unknown function, which represent the majority of pathogen-specific proteins (presumably involved in virulence mechanisms), were underrepresented. Characterization of various L. interrogans exoprotein mutants in the animal infection model revealed host mortality rates similar to those of hosts infected with wild-type L. interrogans. Collectively, these results indicate that pathogenic Leptospira exoproteins primarily function in heterotrophic processes (the processes by which organisms utilize organic substances as nutrient sources) to maintain the saprophytic lifestyle rather than the virulence of the bacteria. The underrepresentation of proteins homologous to known virulence factors, such as toxins and effectors in the exoproteome, also suggests that disease manifesting from Leptospira infection is likely caused by a combination of the primary and potentially moonlight functioning of exoproteins.
Collapse
Affiliation(s)
- Azad Eshghi
- Institut Pasteur, Biology of Spirochetes Unit, Paris, France
| | - Elisa Pappalardo
- University of Oxford, Sir William Dunn School of Pathology, Oxford, United Kingdom
| | - Svenja Hester
- University of Oxford, Sir William Dunn School of Pathology, Oxford, United Kingdom
| | - Benjamin Thomas
- University of Oxford, Sir William Dunn School of Pathology, Oxford, United Kingdom
| | - Gabriela Pretre
- Institut Pasteur, Biology of Spirochetes Unit, Paris, France
| | | |
Collapse
|
24
|
Abstract
Vaccines against leptospirosis followed within a year of the first isolation of Leptospira, with the first use of a killed whole cell bacterin vaccine in guinea pigs published in 1916. Since then, bacterin vaccines have been used in humans, cattle, swine, and dogs and remain the only vaccines licensed at the present time. The immunity elicited is restricted to serovars with related lipopolysaccharide (LPS) antigen. Likewise, vaccines based on LPS antigens have clearly demonstrated protection in animal models, which is also at best serogroup specific. The advent of leptospiral genome sequences has allowed a reverse vaccinology approach for vaccine development. However, the use of inadequate challenge doses and inappropriate statistical analysis invalidates many of the claims of protection with recombinant proteins.
Collapse
Affiliation(s)
- Ben Adler
- Department of Microbiology, Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, VIC, 3800, Australia,
| |
Collapse
|
25
|
Abstract
The mechanisms of disease pathogenesis in leptospirosis are poorly defined. Recent developments in the application of genetic tools in the study of Leptospira have advanced our understanding by allowing the assessment of mutants in animal models. As a result, a small number of essential virulence factors have been identified, though most do not have a clearly defined function. Significant advances have also been made in the in vitro characterization of leptospiral interaction with host structures, including extracellular matrix proteins (such as laminin, elastin, fibronectin, collagens), proteins related to hemostasis (fibrinogen, plasmin), and soluble mediators of complement resistance (factor H, C4b-binding protein), although none of these in vitro findings has been translated to the host animal. Binding to host structures may permit colonization of the host, prevention of blood clotting may contribute to hemorrhage, while interaction with complement resistance mediators may contribute to survival in serum. While not a classical intracellular pathogen, the interaction of leptospires and phagocytic cells appears complex, with bacteria surviving uptake and promoting apoptosis; mutants relating to these processes (such as cell invasion and oxidative stress resistance) are attenuated in vivo. Another feature of leptospiral biology is the high degree of functional redundancy and the surprising lack of attenuation of mutants in what appear to be certain virulence factors, such as LipL32 and LigB. While many advances have been made, there remains a lack of understanding of how Leptospira causes tissue pathology. It is likely that leptospires have many novel pathogenesis mechanisms that are yet to be identified.
Collapse
|
26
|
Scornec H, Tichit M, Bouchier C, Pédron T, Cavin JF, Sansonetti PJ, Licandro-Seraut H. Rapid 96-well plates DNA extraction and sequencing procedures to identify genome-wide transposon insertion sites in a difficult to lyse bacterium: Lactobacillus casei. J Microbiol Methods 2014; 106:78-82. [PMID: 25135488 DOI: 10.1016/j.mimet.2014.08.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 08/04/2014] [Accepted: 08/05/2014] [Indexed: 11/18/2022]
Abstract
Random transposon mutagenesis followed by adequate screening methods is an unavoidable procedure to characterize genetics of bacterial adaptation to environmental changes. We have recently constructed a mutant library of Lactobacillus casei and we aimed to fully annotate it. However, we have observed that, for L. casei which is a difficult to lyse bacterium, methods used to identify the transposon insertion site in a few mutants (transposon rescue by restriction and recircularization or PCR-based methods) were not transposable for a larger number because they are too time-consuming and sometimes not reliable. Here, we describe a method for large-scale and reliable identification of transposon insertion sites in a L. casei mutant library of 9250 mutants. DNA extraction procedure based on silica membranes in 96-column format was optimized to obtain genomic DNA from a large number of mutants. Then reliable direct genomic sequencing was improved to fit the obtained genomic DNA extracts. Using this procedure, readable and identifiable sequences were obtained for 87% of the L. casei mutants. This method extends the applications of a library of this type, reduces the number of insertions needed to be screened, and allows selection of specific mutants from an arrayed and stored mutant library. This method is applicable to any already existing mutant library (obtained by transposon or insertional mutagenesis) and could be useful for other bacterial species, especially for highly lysis-resistant bacteria species such as lactic acid bacteria.
Collapse
Affiliation(s)
- Hélène Scornec
- UMR A PAM, AgroSup Dijon/Université de Bourgogne, 1 Esplanade Erasme, 21000, Dijon, France
| | - Magali Tichit
- Plate-forme Génomique, Département Génomes et Génétique, Institut Pasteur, 28 Rue du Docteur Roux, 75724, Paris cedex 15, France
| | - Christiane Bouchier
- Plate-forme Génomique, Département Génomes et Génétique, Institut Pasteur, 28 Rue du Docteur Roux, 75724, Paris cedex 15, France
| | - Thierry Pédron
- Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, 28 Rue du Docteur Roux, 75724, Paris cedex 15, France; Unité INSERM 786, Institut Pasteur, Paris, France
| | - Jean-François Cavin
- UMR A PAM, AgroSup Dijon/Université de Bourgogne, 1 Esplanade Erasme, 21000, Dijon, France
| | - Philippe J Sansonetti
- Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, 28 Rue du Docteur Roux, 75724, Paris cedex 15, France; Unité INSERM 786, Institut Pasteur, Paris, France; Chaire de Microbiologie et Maladies Infectieuses, Collège de France, 11 Place Marcelin Berthelot, 75005, Paris, France.
| | - Hélène Licandro-Seraut
- UMR A PAM, AgroSup Dijon/Université de Bourgogne, 1 Esplanade Erasme, 21000, Dijon, France; Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, 28 Rue du Docteur Roux, 75724, Paris cedex 15, France
| |
Collapse
|
27
|
Pathogenesis of leptospirosis: Cellular and molecular aspects. Vet Microbiol 2014; 172:353-8. [DOI: 10.1016/j.vetmic.2014.06.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 06/09/2014] [Accepted: 06/14/2014] [Indexed: 11/23/2022]
|
28
|
Lehmann JS, Matthias MA, Vinetz JM, Fouts DE. Leptospiral pathogenomics. Pathogens 2014; 3:280-308. [PMID: 25437801 PMCID: PMC4243447 DOI: 10.3390/pathogens3020280] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Revised: 03/22/2014] [Accepted: 03/28/2014] [Indexed: 11/30/2022] Open
Abstract
Leptospirosis, caused by pathogenic spirochetes belonging to the genus Leptospira, is a zoonosis with important impacts on human and animal health worldwide. Research on the mechanisms of Leptospira pathogenesis has been hindered due to slow growth of infectious strains, poor transformability, and a paucity of genetic tools. As a result of second generation sequencing technologies, there has been an acceleration of leptospiral genome sequencing efforts in the past decade, which has enabled a concomitant increase in functional genomics analyses of Leptospira pathogenesis. A pathogenomics approach, by coupling of pan-genomic analysis of multiple isolates with sequencing of experimentally attenuated highly pathogenic Leptospira, has resulted in the functional inference of virulence factors. The global Leptospira Genome Project supported by the U.S. National Institute of Allergy and Infectious Diseases to which key scientific contributions have been made from the international leptospirosis research community has provided a new roadmap for comprehensive studies of Leptospira and leptospirosis well into the future. This review describes functional genomics approaches to apply the data generated by the Leptospira Genome Project towards deepening our knowledge of virulence factors of Leptospira using the emerging discipline of pathogenomics.
Collapse
Affiliation(s)
- Jason S Lehmann
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, School of Medicine, La Jolla, CA 92093-0741, USA.
| | - Michael A Matthias
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, School of Medicine, La Jolla, CA 92093-0741, USA.
| | - Joseph M Vinetz
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, School of Medicine, La Jolla, CA 92093-0741, USA.
| | | |
Collapse
|
29
|
A model system for studying the transcriptomic and physiological changes associated with mammalian host-adaptation by Leptospira interrogans serovar Copenhageni. PLoS Pathog 2014; 10:e1004004. [PMID: 24626166 PMCID: PMC3953431 DOI: 10.1371/journal.ppat.1004004] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 02/01/2014] [Indexed: 12/23/2022] Open
Abstract
Leptospirosis, an emerging zoonotic disease with worldwide distribution, is caused by spirochetes belonging to the genus Leptospira. More than 500,000 cases of severe leptospirosis are reported annually, with >10% of these being fatal. Leptospires can survive for weeks in suitably moist conditions before encountering a new host. Reservoir hosts, typically rodents, exhibit little to no signs of disease but shed large numbers of organisms in their urine. Transmission occurs when mucosal surfaces or abraded skin come into contact with infected urine or urine-contaminated water or soil. In humans, leptospires can cause a variety of clinical manifestations, ranging from asymptomatic or mild fever to severe icteric (Weil's) disease and pulmonary haemorrhage. Currently, little is known about how Leptospira persist within a reservoir host. Prior in vitro studies have suggested that leptospires alter their transcriptomic and proteomic profiles in response to environmental signals encountered during mammalian infection. However, no study has examined gene expression by leptospires within a mammalian host-adapted state. To obtain a more faithful representation of how leptospires respond to host-derived signals, we used RNA-Seq to compare the transcriptome of L. interrogans cultivated within dialysis membrane chambers (DMCs) implanted into the peritoneal cavities of rats with that of organisms grown in vitro. In addition to determining the relative expression levels of “core” housekeeping genes under both growth conditions, we identified 166 genes that are differentially-expressed by L. interrogans in vivo. Our analyses highlight physiological aspects of host adaptation by leptospires relating to heme uptake and utilization. We also identified 11 novel non-coding transcripts that are candidate small regulatory RNAs. The DMC model provides a facile system for studying the transcriptional and antigenic changes associated with mammalian host-adaption, selection of targets for mutagenesis, and the identification of previously unrecognized virulence determinants. Leptospirosis, a global disease caused by the unusual bacterium Leptospira, is transmitted from animals to humans. Pathogenic species of Leptospira are excreted in urine from infected animals and can continue to survive in suitable environments before coming into contact with a new reservoir or accidental host. Leptospires have an inherent ability to survive a wide range of conditions encountered in nature during transmission and within mammals. However, we know very little about the regulatory pathways and gene products that promote mammalian host adaptation and enable leptospires to establish infection. In this study, we used a novel system whereby leptospires are cultivated in dialysis membrane chambers implanted into the peritoneal cavities of rats to compare the gene expression profiles of mammalian host-adapted and in vitro-cultivated organisms. In addition to providing a facile system for studying the transcriptional and physiologic changes leptospires undergo during mammalian infection, our data provide a rational basis for selecting new targets for mutagenesis.
Collapse
|
30
|
High-temperature protein G is an essential virulence factor of Leptospira interrogans. Infect Immun 2013; 82:1123-31. [PMID: 24366253 DOI: 10.1128/iai.01546-13] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Leptospira interrogans is a global zoonotic pathogen and is the causative agent of leptospirosis, an endemic disease of humans and animals worldwide. There is limited understanding of leptospiral pathogenesis; therefore, further elucidation of the mechanisms involved would aid in vaccine development and the prevention of infection. HtpG (high-temperature protein G) is the bacterial homolog to the highly conserved molecular chaperone Hsp90 and is important in the stress responses of many bacteria. The specific role of HtpG, especially in bacterial pathogenesis, remains largely unknown. Through the use of an L. interrogans htpG transposon insertion mutant, this study demonstrates that L. interrogans HtpG is essential for virulence in the hamster model of acute leptospirosis. Complementation of the htpG mutant completely restored virulence. Surprisingly, the htpG mutant did not appear to show sensitivity to heat or oxidative stress, phenotypes common in htpG mutants in other bacterial species. Furthermore, the mutant did not show increased sensitivity to serum complement, reduced survival within macrophages, or altered protein or lipopolysaccharide expression. The underlying cause for attenuation thus remains unknown, but HtpG is a novel leptospiral virulence factor and one of only a very small number identified to date.
Collapse
|