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Nascimento Filho EG, Vieira ML, Dias M, Mendes MA, Sanchez FB, Setubal JC, Heinemann MB, Souza GO, Pimenta DC, Nascimento ALTO. Global proteome of the saprophytic strain Leptospira biflexa and comparative analysis with pathogenic strain Leptospira interrogans uncover new pathogenesis mechanisms. J Proteomics 2024; 297:105125. [PMID: 38364905 DOI: 10.1016/j.jprot.2024.105125] [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: 06/23/2023] [Revised: 01/08/2024] [Accepted: 02/05/2024] [Indexed: 02/18/2024]
Abstract
Leptospira is a genus of bacteria that includes free-living saprophytic species found in water or soil, and pathogenic species, which are the etiologic agents of leptospirosis. Besides all the efforts, there are only a few proteins described as virulence factors in the pathogenic strain L. interrogans. This work aims to perform L. biflexa serovar Patoc1 strain Paris global proteome and to compare with the proteome database of pathogenic L. interrogans serovar Copenhageni strain Fiocruz L1-130. We identified a total of 2327 expressed proteins of L. biflexa by mass spectrometry. Using the Get Homologues software with the global proteome of L. biflexa and L. interrogans, we found orthologous proteins classified into conserved, low conserved, and specific proteins. Comparative bioinformatic analyses were performed to understand the biological functions of the proteins, subcellular localization, the presence of signal peptide, structural domains, and motifs using public softwares. These results lead to the selection of 182 low conserved within the saprophyte, and 176 specific proteins of L. interrogans. It is anticipated that these findings will indicate further studies to uncover virulence factors in the pathogenic strain. This work presents for the first time the global proteome of saprophytic strain L. biflexa serovar Patoc, strain Patoc1. SIGNIFICANCE: The comparative analysis established an array of specific proteins in pathogenic strain that will narrow down the identification of immune protective proteins that will help fight leptospirosis.
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Affiliation(s)
- Edson G Nascimento Filho
- Laboratorio de Desenvolvimento de Vacinas, Instituto Butantan, SP, Brazil; Programa de Pos-Graduacao em Biotecnologia, USP-IBU-IPT, SP, Brazil
| | - Mônica L Vieira
- Departmento de Microbiologia, Instituto de Ciências Biológicas, UFMG, MG, Brazil
| | - Meriellen Dias
- Laboratorio Dempster, Departamento de Engenharia Química, Escola Politécnica, USP, SP, Brazil
| | - Maria A Mendes
- Laboratorio Dempster, Departamento de Engenharia Química, Escola Politécnica, USP, SP, Brazil
| | | | | | - Marcos B Heinemann
- Laboratório de Zoonoses Bacterianas do VPS, Faculdade de Medicina Veterinária e Zootecnia, USP, SP, Brazil
| | - Gisele O Souza
- Laboratório de Zoonoses Bacterianas do VPS, Faculdade de Medicina Veterinária e Zootecnia, USP, SP, Brazil
| | | | - Ana L T O Nascimento
- Laboratorio de Desenvolvimento de Vacinas, Instituto Butantan, SP, Brazil; Programa de Pos-Graduacao em Biotecnologia, USP-IBU-IPT, SP, Brazil.
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2
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Kumar P, Lata S, Shankar UN, Akif M. Immunoinformatics-Based Designing of a Multi-Epitope Chimeric Vaccine From Multi-Domain Outer Surface Antigens of Leptospira. Front Immunol 2021; 12:735373. [PMID: 34917072 PMCID: PMC8670241 DOI: 10.3389/fimmu.2021.735373] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/08/2021] [Indexed: 11/13/2022] Open
Abstract
Accurate information on antigenic epitopes within a multi-domain antigen would provide insights into vaccine design and immunotherapy. The multi-domain outer surface Leptospira immunoglobulin-like (Lig) proteins LigA and LigB, consisting of 12–13 homologous bacterial Ig (Big)-like domains, are potential antigens of Leptospira interrogans. Currently, no effective vaccine is available against pathogenic Leptospira. Both the humoral immunity and cell-mediated immunity of the host play critical roles in defending against Leptospira infection. Here, we used immunoinformatics approaches to evaluate antigenic B-cell lymphocyte (BCL) and cytotoxic T-lymphocyte (CTL) epitopes from Lig proteins. Based on certain crucial parameters, potential epitopes that can stimulate both types of adaptive immune responses were selected to design a chimeric vaccine construct. Additionally, an adjuvant, the mycobacterial heparin-binding hemagglutinin adhesin (HBHA), was incorporated into the final multi-epitope vaccine construct with a suitable linker. The final construct was further scored for its antigenicity, allergenicity, and physicochemical parameters. A three-dimensional (3D) modeled construct of the vaccine was implied to interact with Toll-like receptor 4 (TLR4) using molecular docking. The stability of the vaccine construct with TLR4 was predicted with molecular dynamics simulation. Our results demonstrate the application of immunoinformatics and structure biology strategies to develop an epitope-specific chimeric vaccine from multi-domain proteins. The current findings will be useful for future experimental validation to ratify the immunogenicity of the chimera.
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Affiliation(s)
- Pankaj Kumar
- Laboratory of Structural Biology, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Surabhi Lata
- Laboratory of Structural Biology, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Umate Nachiket Shankar
- Laboratory of Structural Biology, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Mohd Akif
- Laboratory of Structural Biology, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
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3
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Daroz BB, Fernandes LGV, Cavenague MF, Kochi LT, Passalia FJ, Takahashi MB, Nascimento Filho EG, Teixeira AF, Nascimento ALTO. A Review on Host- Leptospira Interactions: What We Know and Future Expectations. Front Cell Infect Microbiol 2021; 11:777709. [PMID: 34900757 PMCID: PMC8657130 DOI: 10.3389/fcimb.2021.777709] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 11/04/2021] [Indexed: 01/01/2023] Open
Abstract
Leptospirosis is a widespread zoonosis caused by pathogenic Leptospira spp. It is considered a neglected infectious disease of human and veterinary concern. Our group has been investigating proteins annotated as hypothetical, predicted to be located on the leptospiral surface. Because of their location, these proteins may have the ability to interact with various host components, which could allow establishment of the infection. These proteins act as adherence factors by binding to host receptor molecules, such as the extracellular matrix (ECM) components laminin and glycosaminoglycans to help bacterial colonization. Leptospira also interacts with the host fibrinolytic system, which has been demonstrated to be a powerful tool for invasion mechanisms. The interaction with fibrinogen and thrombin has been shown to reduce fibrin clot formation. Additionally, the degradation of coagulation cascade components by secreted proteases or by acquired surface plasmin could also play a role in reducing clot formation, hence facilitating dissemination during infection. Interaction with host complement system regulators also plays a role in helping bacteria to evade the immune system, facilitating invasion. Interaction of Leptospira to cell receptors, such as cadherins, can contribute to investigate molecules that participate in virulence. To achieve a better understanding of the host-pathogen interaction, leptospiral mutagenesis tools have been developed and explored. This work presents several proteins that mediate binding to components of the ECM, plasma, components of the complement system and cells, to gather research achievements that can be helpful in better understanding the mechanisms of leptospiral-host interactions and discuss genetic manipulation for Leptospira spp. aimed at protein function validation.
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Affiliation(s)
- Brenda B Daroz
- Laboratorio de Desenvolvimento de Vacinas, Instituto Butantan, Avenida Vital Brazil, Sao Paulo, Brazil.,Programa de Pos-Graduacao Interunidades em Biotecnologia, Instituto de Ciencias Biomedicas, Universidade de São Paulo, Sao Paulo, Brazil
| | - Luis G V Fernandes
- Laboratorio de Desenvolvimento de Vacinas, Instituto Butantan, Avenida Vital Brazil, Sao Paulo, Brazil
| | - Maria F Cavenague
- Laboratorio de Desenvolvimento de Vacinas, Instituto Butantan, Avenida Vital Brazil, Sao Paulo, Brazil.,Programa de Pos-Graduacao Interunidades em Biotecnologia, Instituto de Ciencias Biomedicas, Universidade de São Paulo, Sao Paulo, Brazil
| | - Leandro T Kochi
- Laboratorio de Desenvolvimento de Vacinas, Instituto Butantan, Avenida Vital Brazil, Sao Paulo, Brazil.,Programa de Pos-Graduacao Interunidades em Biotecnologia, Instituto de Ciencias Biomedicas, Universidade de São Paulo, Sao Paulo, Brazil
| | - Felipe J Passalia
- Laboratorio de Desenvolvimento de Vacinas, Instituto Butantan, Avenida Vital Brazil, Sao Paulo, Brazil.,Programa de Pos-Graduacao Interunidades em Biotecnologia, Instituto de Ciencias Biomedicas, Universidade de São Paulo, Sao Paulo, Brazil
| | - Maria B Takahashi
- Laboratorio de Desenvolvimento de Vacinas, Instituto Butantan, Avenida Vital Brazil, Sao Paulo, Brazil.,Programa de Pos-Graduacao Interunidades em Biotecnologia, Instituto de Ciencias Biomedicas, Universidade de São Paulo, Sao Paulo, Brazil
| | - Edson G Nascimento Filho
- Laboratorio de Desenvolvimento de Vacinas, Instituto Butantan, Avenida Vital Brazil, Sao Paulo, Brazil.,Programa de Pos-Graduacao Interunidades em Biotecnologia, Instituto de Ciencias Biomedicas, Universidade de São Paulo, Sao Paulo, Brazil
| | - Aline F Teixeira
- Laboratorio de Desenvolvimento de Vacinas, Instituto Butantan, Avenida Vital Brazil, Sao Paulo, Brazil
| | - Ana L T O Nascimento
- Laboratorio de Desenvolvimento de Vacinas, Instituto Butantan, Avenida Vital Brazil, Sao Paulo, Brazil.,Programa de Pos-Graduacao Interunidades em Biotecnologia, Instituto de Ciencias Biomedicas, Universidade de São Paulo, Sao Paulo, Brazil
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4
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Ho JD, Takara LEM, Monaris D, Gonçalves AP, Souza-Filho AF, de Souza GO, Heinemann MB, Ho PL, Abreu PAE. GroEL protein of the Leptospira spp. interacts with host proteins and induces cytokines secretion on macrophages. BMC Microbiol 2021; 21:99. [PMID: 33789603 PMCID: PMC8011160 DOI: 10.1186/s12866-021-02162-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 03/22/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Leptospirosis is a zoonotic disease caused by infection with spirochetes from Leptospira genus. It has been classified into at least 17 pathogenic species, with more than 250 serologic variants. This wide distribution may be a result of leptospiral ability to colonize the renal tubules of mammalian hosts, including humans, wildlife, and many domesticated animals. Previous studies showed that the expression of proteins belonging to the microbial heat shock protein (HSP) family is upregulated during infection and also during various stress stimuli. Several proteins of this family are known to have important roles in the infectious processes in other bacteria, but the role of HSPs in Leptospira spp. is poorly understood. In this study, we have evaluated the capacity of the protein GroEL, a member of HSP family, of interacting with host proteins and of stimulating the production of cytokines by macrophages. RESULTS The binding experiments demonstrated that the recombinant GroEL protein showed interaction with several host components in a dose-dependent manner. It was also observed that GroEL is a surface protein, and it is secreted extracellularly. Moreover, two cytokines (tumor necrosis factor-α and interleukin-6) were produced when macrophages cells were stimulated with this protein. CONCLUSIONS Our findings showed that GroEL protein may contribute to the adhesion of leptospires to host tissues and stimulate the production of proinflammatory cytokines during infection. These features might indicate an important role of GroEL in the pathogen-host interaction in the leptospirosis.
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Affiliation(s)
- Joana Dias Ho
- Laboratory of Bacteriology, Butantan Institute, São Paulo, Brazil.,Laboratory of Bacterial Zoonosis, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | | | - Denize Monaris
- Laboratory of Bacteriology, Butantan Institute, São Paulo, Brazil
| | | | - Antonio Francisco Souza-Filho
- Laboratory of Bacterial Zoonosis, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Gisele Oliveira de Souza
- Laboratory of Bacterial Zoonosis, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Marcos Bryan Heinemann
- Laboratory of Bacterial Zoonosis, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Paulo Lee Ho
- Bioindustrial Division, Butantan Institute, São Paulo, Brazil
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5
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Haake DA, Matsunaga J. Leptospiral Immunoglobulin-Like Domain Proteins: Roles in Virulence and Immunity. Front Immunol 2021; 11:579907. [PMID: 33488581 PMCID: PMC7821625 DOI: 10.3389/fimmu.2020.579907] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 11/05/2020] [Indexed: 02/03/2023] Open
Abstract
The virulence mechanisms required for infection and evasion of immunity by pathogenic Leptospira species remain poorly understood. A number of L. interrogans surface proteins have been discovered, lying at the interface between the pathogen and host. Among these proteins, the functional properties of the Lig (leptospiral immunoglobulin-like domain) proteins have been examined most thoroughly. LigA, LigB, and LigC contain a series of, 13, 12, and 12 closely related domains, respectively, each containing a bacterial immunoglobulin (Big) -like fold. The multidomain region forms a mostly elongated structure that exposes a large surface area. Leptospires wield the Lig proteins to promote interactions with a range of specific host proteins, including those that aid evasion of innate immune mechanisms. These diverse binding events mediate adhesion of L. interrogans to the extracellular matrix, inhibit hemostasis, and inactivate key complement proteins. These interactions may help L. interrogans overcome the physical, hematological, and immunological barriers that would otherwise prevent the spirochete from establishing a systemic infection. Despite significant differences in the affinities of the LigA and LigB proteins for host targets, their functions overlap during lethal infection of hamsters; virulence is lost only when both ligA and ligB transcription is knocked down simultaneously. Lig proteins have been shown to be promising vaccine antigens through evaluation of a variety of different adjuvant strategies. This review serves to summarize current knowledge of Lig protein roles in virulence and immunity and to identify directions needed to better understand the precise functions of the Lig proteins during infection.
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Affiliation(s)
- David A. Haake
- Division of Infectious Diseases, VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States
- Departments of Medicine, and Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, United States
| | - James Matsunaga
- Research Service, VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, United States
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6
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AAA+ Molecular Chaperone ClpB in Leptospira interrogans: Its Role and Significance in Leptospiral Virulence and Pathogenesis of Leptospirosis. Int J Mol Sci 2020; 21:ijms21186645. [PMID: 32932775 PMCID: PMC7555560 DOI: 10.3390/ijms21186645] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/31/2020] [Accepted: 09/08/2020] [Indexed: 02/06/2023] Open
Abstract
Bacterial ClpB is an ATP-dependent disaggregase that belongs to the Hsp100/Clp subfamily of the AAA+ ATPases and cooperates with the DnaK chaperone system in the reactivation of aggregated proteins, as well as promotes bacterial survival under adverse environmental conditions, including thermal and oxidative stresses. In addition, extensive evidence indicates that ClpB supports the virulence of numerous bacteria, including pathogenic spirochaete Leptospira interrogans responsible for leptospirosis in animals and humans. However, the specific function of ClpB in leptospiral virulence still remains to be fully elucidated. Interestingly, ClpB was predicted as one of the L. interrogans hub proteins interacting with human proteins, and pathogen–host protein interactions are fundamental for successful invasion of the host immune system by bacteria. The aim of this review is to discuss the most important aspects of ClpB’s function in L. interrogans, including contribution of ClpB to leptospiral virulence and pathogenesis of leptospirosis, a zoonotic disease with a significant impact on public health worldwide.
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7
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Prabhu D, Rajamanikandan S, Anusha SB, Chowdary MS, Veerapandiyan M, Jeyakanthan J. In silico Functional Annotation and Characterization of Hypothetical Proteins from Serratia marcescens FGI94. BIOL BULL+ 2020; 47:319-331. [PMID: 32834707 PMCID: PMC7394047 DOI: 10.1134/s1062359020300019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 09/28/2019] [Accepted: 09/30/2019] [Indexed: 01/16/2023]
Abstract
Serratia marcescens, rod-shaped Gram-negative bacteria is classified as an opportunistic pathogen in the family Enterobacteriaceae. It causes a wide variety of infections in humans, including urinary, respiratory, ocular lens and ear infections, osteomyelitis, endocarditis, meningitis and septicemia. Unfortunately, over the past decade, antibiotic resistance has become a serious health care issue; the effective means to control and dissemination of S. marcescens resistance is the need of hour. The whole genome sequencing of S. marcescens FGI94 strain contains 4434 functional proteins, among which 690 (15.56%) proteins were classified under hypothetical. In the present study, we applied the power of various bioinformatics tools on the basis of protein family comparison, motifs, functional properties of amino acids and genome context to assign the possible functions for the HPs. The pseudo sequences (protein sequence that contain ≤100 amino acid residues) are eliminated from the study. Although we have successfully predicted the function for 483 proteins, we were able to infer the high level of confidence only for 108 proteins. The predicted HPs were classified into various classes such as enzymes, transporters, binding proteins, cell division, cell regulatory and other proteins. The outcome of the study could be helpful to understand the molecular mechanism in bacterial pathogenesis and also provide an insight into the identification of potential targets for drug and vaccine development.
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Affiliation(s)
- D Prabhu
- Department of Bioinformatics, Alagappa University, Science Campus, 630004 Karaikudi, Tamil Nadu India
| | - S Rajamanikandan
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics, 560064 Yelahanka, Bengaluru India
| | - S Baby Anusha
- Department of Bioinformatics, Sathyabama University, 600119 Chennai, Tamil Nadu India
| | - M Sushma Chowdary
- Department of Bioinformatics, Sathyabama University, 600119 Chennai, Tamil Nadu India
| | - M Veerapandiyan
- Department of Bioinformatics, Alagappa University, Science Campus, 630004 Karaikudi, Tamil Nadu India
| | - J Jeyakanthan
- Department of Bioinformatics, Alagappa University, Science Campus, 630004 Karaikudi, Tamil Nadu India
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8
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Barbosa AS, Isaac L. Strategies used by Leptospira spirochetes to evade the host complement system. FEBS Lett 2020; 594:2633-2644. [PMID: 32153015 DOI: 10.1002/1873-3468.13768] [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: 11/15/2019] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 12/19/2022]
Abstract
Leptospires are highly invasive spirochetes equipped with efficient strategies for dissemination in the host. The Leptospira genus currently comprises 64 species divided into two major clades: the saprophytes composed of nonpathogenic, free-living organisms, and the pathogens encompassing all the species that cause mild or severe infections in humans and animals. While saprophytes are highly susceptible to the lytic action of the complement system, pathogenic (virulent) strains have evolved virulence strategies that allow efficient colonization of a variety of hosts and target organs, including mechanisms to circumvent hosts' innate and acquired immune responses. Pathogenic Leptospira avoid complement-mediated killing by recruiting host complement regulatory proteins and by targeting complement proteins using own and host-expressed proteases. This review outlines the role of complement in eradicating saprophytic Leptospira and the stratagems adopted by pathogenic Leptospira to maneuver the host complement system for their benefit.
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Affiliation(s)
| | - Lourdes Isaac
- Laboratory of Complement, Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, Brazil
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9
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Vieira ML, Herwald H, Nascimento ALTO. The interplay between host haemostatic systems and Leptospira spp. infections. Crit Rev Microbiol 2020; 46:121-135. [PMID: 32141788 DOI: 10.1080/1040841x.2020.1735299] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hemostasis is a defence mechanism that protects the integrity of the vascular system and is comprised of the coagulation cascade, fibrinolysis, platelet aggregation, and vascular endothelium. Besides the primary function in preserving the vascular integrity, the haemostatic system cooperates with immune and inflammatory processes to eliminate invading pathogens during microbial infections. Under pathological manifestations, hemostasis must therefore interact in a coordinated manner with inflammatory responses and immune reactions. Several pathogens can modulate these host-derived countermeasures by specifically targeting certain haemostatic components for their own benefit. Thus, the ability to modulate host defence systems has to be considered as an essential bacterial virulence mechanism. Complications that bacterial pathogens can induce are therefore often the consequence of evoked host responses. A comprehensive understanding of the molecular mechanisms triggered in infectious processes may help to develop prophylactic methods and novel therapies for the patients suffering from a particular infectious disease. This review aims to provide a critical updated compiling of recent studies on how the pathogenic Leptospira can interact with and manipulate the host haemostatic systems and the consequences for leptospirosis pathogenesis.
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Affiliation(s)
- Monica L Vieira
- Department of Microbiology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Heiko Herwald
- Department of Clinical Sciences, Lund, Division of Infection Medicine, Lund University, Lund, Sweden
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10
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Role of Supramolecule ErpY-Like Lipoprotein of Leptospira in Thrombin-Catalyzed Fibrin Clot Inhibition and Binding to Complement Factors H and I, and Its Diagnostic Potential. Infect Immun 2019; 87:IAI.00536-19. [PMID: 31548314 DOI: 10.1128/iai.00536-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 09/12/2019] [Indexed: 01/12/2023] Open
Abstract
Leptospirosis is one of the most widespread zoonoses caused by pathogenic Leptospira spp. In this study, we report that the LIC11966/ErpY-like lipoprotein is a surface-exposed outer membrane protein exclusively present in pathogenic species of Leptospira The recombinant ErpY (rErpY)-like protein is recognized by the immunoglobulins of confirmed leptospirosis sera of diverse hosts (human, bovine, and canine), suggesting the expression of the native leptospiral surface protein during infection. Circular dichroism of pure rErpY-like protein showed the secondary structural integrity to be uncompromised during the purification process. Analysis of the rErpY-like protein by native polyacrylamide gel electrophoresis, chemical cross-linking, dynamic light scattering, and field emission transmission electron microscopy demonstrated it undergoes supramolecular assembly. The rErpY-like protein can bind to diverse host extracellular matrices, and it presented a saturable and strong binding affinity (dissociation constant [KD ] of 70.45 ± 4.13 nM) to fibrinogen, a central host plasma component involved in blood clotting. In the presence of the rErpY-like supramolecule, thrombin-catalyzed fibrin clot formation is inhibited up to 7%, implying its role in inhibiting blood coagulation during Leptospira infection. In addition, binding of the rErpY-like supramolecule to complement factors H and I suggests the protein also contributes to Leptospira evading innate host defense during infection by inactivating alternative complement pathways. This study reveals that rErpY-like protein is functionally active in the supramolecular state and performs moonlighting activity under the given in vitro conditions.
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11
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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.
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Affiliation(s)
- Mathieu Picardeau
- Biology of Spirochetes Unit, Institut Pasteur, 28 Rue Du Docteur Roux, 75724, Paris Cedex 15, France.
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12
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Abstract
Temperature variation is one of the multiple parameters a microbial pathogen encounters when it invades a warm-blooded host. To survive and thrive at host body temperature, human pathogens have developed various strategies to sense and respond to their ambient temperature. An instantaneous response is mounted by RNA thermometers (RNATs), which are integral sensory structures in mRNAs that modulate translation efficiency. At low temperatures outside the host, the folded RNA blocks access of the ribosome to the translation initiation region. The temperature shift upon entering the host destabilizes the RNA structure and thus permits ribosome binding. This reversible zipper-like mechanism of RNATs is ideally suited to fine-tune virulence gene expression when the pathogen enters or exits the body of its host. This review summarizes our present knowledge on virulence-related RNATs and discusses recent developments in the field.
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13
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Pawar AD, Verma D, Sankeshi V, Raman R, Sharma Y. Strategizing for the purification of a multiple Big domain-containing protein in native conformation is worth it! Protein Expr Purif 2017; 145:25-31. [PMID: 29287899 DOI: 10.1016/j.pep.2017.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 12/15/2017] [Accepted: 12/21/2017] [Indexed: 11/30/2022]
Abstract
The reliability and accuracy of conformational or functional studies of any novel multidomain protein rely on the quality of protein. The bottleneck in structural studies with the complete Big_2 domain containing proteins like LigA, LigB or MpIBP is usually their large molecular size owing to their multidomain (>10-12 domains) architectures. Interestingly, a soil bacterium Paenarthrobacter aurescens TC1, harbours a gene that encodes a protein comprising of four predicted Big_2 domains. We report here the expression and purification of this novel, multiple Big_2 domains containing protein, Arig of P. aurescens TC1. During overexpression, recombinant Arig formed inclusion bodies and hence was purified by on-column refolding. The refolded Arig revealed a β-sheet conformation and a well-resolved near-UV CD spectra but did not exhibit a well-dispersed 2D [1H-15N]-HSQC NMR spectrum, as expected for a well-folded β-sheet native conformation. We, therefore, further optimized Arig overexpression in the soluble fraction by including osmolytes. CD spectroscopic and 2D [1H-15N]-HSQC analyses consolidate that Arig purified alternatively has a well-folded native conformation. While we describe different strategies for purification of Arig, we also present the spectral properties of this novel all-β-sheet protein.
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Affiliation(s)
- Asmita D Pawar
- CSIR-Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Hyderabad 500 007, India.
| | - Deepshikha Verma
- Department of Chemical Sciences, Tata Institute of Fundamental Research, 1, Homi Bhabha Road, Colaba, Mumbai, 400005, India
| | - Venu Sankeshi
- CSIR-Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Hyderabad 500 007, India
| | - Rajeev Raman
- CSIR-Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Hyderabad 500 007, India
| | - Yogendra Sharma
- CSIR-Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Hyderabad 500 007, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi, India
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14
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[Differentiation of pathogenic leptospires spp by PCR of ligB gene and sequencing]. Rev Argent Microbiol 2017; 50:126-130. [PMID: 29066033 DOI: 10.1016/j.ram.2016.11.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 10/28/2016] [Accepted: 11/28/2016] [Indexed: 11/21/2022] Open
Abstract
Leptospirosis is a zoonosis having worldwide distribution. The objective of this work was to develop a molecular technique to differentiate pathogenic Leptospira spp. A region of adhesin ligB, present only in the pathogenic species was amplified by PCR and sequenced. ligBRpet and ligBFpet primers were used, which amplified the target DNA from pathogenic L. interrogans reference strains serovars Pomona strain Pomona, Canicola strain Hond Utrecht IV, Copenhageni strain M 20, Wolffi strain 3705, Pyrogenes strain Salinem, Hardjo strain Hardjoprajitmo, L. borgpetersenii serovar Castellonis strain Castellon 3 and 4 pathogenic strains isolated from bovines, pigs, rats and opossums. L. biflexa serovars Patoc strain Patoc I and Andamana strain Andamana were not amplified. Sequencing of the amplified products exhibited sufficient variation among serovars, which differentiates them.
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Evangelista KV, Lourdault K, Matsunaga J, Haake DA. Immunoprotective properties of recombinant LigA and LigB in a hamster model of acute leptospirosis. PLoS One 2017; 12:e0180004. [PMID: 28704385 PMCID: PMC5509140 DOI: 10.1371/journal.pone.0180004] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 06/05/2017] [Indexed: 12/05/2022] Open
Abstract
Leptospirosis is the most widespread zoonosis and is considered a major public health problem worldwide. Currently, there is no widely available vaccine against leptospirosis for use in humans. A purified, recombinant subunit vaccine that includes the last six immunoglobulin-like (Ig-like) domains of the leptospiral protein LigA (LigA7'-13) protects against lethal infection but not renal colonization after challenge by Leptospira interrogans. In this study, we examined whether the addition of the first seven Ig-like domains of LigB (LigB0-7) to LigA7'-13, can enhance immune protection and confer sterilizing immunity in the Golden Syrian hamster model of acute leptospirosis. Hamsters were subcutaneously immunized with soluble, recombinant LigA7'-13, LigB0-7, or a combination of LigA7'-13 and LigB0-7 in Freund's adjuvant. Immunization with Lig proteins generated a strong humoral immune response with high titers of IgG that recognized homologous protein, and cross-reacted with the heterologous protein as assessed by ELISA. LigA7'-13 alone, or in combination with LigB0-7, protected all hamsters from intraperitoneal challenge with a lethal dose of L. interrogans serovar Copenhageni strain Fiocruz L1-130. However, bacteria were recovered from the kidneys of all animals. Of eight animals immunized with LigB0-7, only three survived Leptospira challenge, one of which lacked renal colonization and had antibodies to native LigB by immunoblot. In addition, sera from two of the three LigB0-7 immunized survivors cross-reacted with LigA11-13, a region of LigA that is sufficient for protection. In summary, we confirmed that LigA7'-13 protects hamsters from death but not infection, and immunization with LigB0-7, either alone or in combination with LigA7'-13, did not confer sterilizing immunity.
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Affiliation(s)
- Karen V. Evangelista
- Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
| | - Kristel Lourdault
- Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
| | - James Matsunaga
- Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
| | - David A. Haake
- Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
- Department of Urology, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
- Department of Microbiology, Immunology and Molecular Genetics, UCLA, Los Angeles, California, United States of America
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Multifunctional and Redundant Roles of Leptospira interrogans Proteins in Bacterial-Adhesion and fibrin clotting inhibition. Int J Med Microbiol 2017; 307:297-310. [PMID: 28600123 DOI: 10.1016/j.ijmm.2017.05.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 05/16/2017] [Accepted: 05/28/2017] [Indexed: 02/01/2023] Open
Abstract
Pathogenic Leptopira is the etiological agent of leptospirosis, the most widespread zoonotic infection in the world. The disease represents a major public health problem, especially in tropical countries. The present work focused on two hypothetical proteins of unknown function, encoded by the genes LIC13059 and LIC10879, and predicted to be surface-exposed proteins. The genes were cloned and the proteins expressed using E. coli as a host system. We report that the recombinant proteins interacted with extracellular matrix (ECM) laminin, in a dose-dependent fashion and are novel potential adhesins. The recombinant proteins were called Lsa25.6 (rLIC13059) and Lsa16 (rLIC10879), for Leptospiral surface adhesins, followed by the respective molecular masses. The proteins attached to plasminogen (PLG), generating plasmin, in the presence of PLG-activator uPA. Both proteins bind to fibrinogen (Fg), but only Lsa25.6 inhibited fibrin clotting by thrombin-catalyzed reaction. Moreover, Lsa16 interacts with the mammalian cell receptor E-cadherin, and could contribute to bacterial attachment to epithelial cells. The proteins were recognized by confirmed leptospirosis serum samples, suggesting that they are expressed during infection. The corresponding leptospiral proteins are surface exposed based on proteinase K accessibility assay, being LIC10879 most probably exposed in its dimer form. The data of this study extend the spectrum of surface-exposed proteins of L. interrogans and indicate a possible role of the originally annotated hypothetical proteins in infection processes.
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LigB subunit vaccine confers sterile immunity against challenge in the hamster model of leptospirosis. PLoS Negl Trop Dis 2017; 11:e0005441. [PMID: 28301479 PMCID: PMC5370146 DOI: 10.1371/journal.pntd.0005441] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Revised: 03/28/2017] [Accepted: 02/27/2017] [Indexed: 11/29/2022] Open
Abstract
Neglected tropical diseases, including zoonoses such as leptospirosis, have a major impact on rural and poor urban communities, particularly in developing countries. This has led to major investment in antipoverty vaccines that focus on diseases that influence public health and thereby productivity. While the true, global, impact of leptospirosis is unknown due to the lack of adequate laboratory diagnosis, the WHO estimates that incidence has doubled over the last 15 years to over 1 million cases that require hospitalization every year. Leptospirosis is caused by pathogenic Leptospira spp. and is spread through direct contact with infected animals, their urine or contaminated water and soil. Inactivated leptospirosis vaccines, or bacterins, are approved in only a handful of countries due to the lack of heterologous protection (there are > 250 pathogenic Leptospira serovars) and the serious side-effects associated with vaccination. Currently, research has focused on recombinant vaccines, a possible solution to these problems. However, due to a lack of standardised animal models, rigorous statistical analysis and poor reproducibility, this approach has met with limited success. We evaluated a subunit vaccine preparation, based on a conserved region of the leptospiral immunoglobulin-like B protein (LigB(131–645)) and aluminium hydroxide (AH), in the hamster model of leptospirosis. The vaccine conferred significant protection (80.0–100%, P < 0.05) against mortality in vaccinated animals in seven independent experiments. The efficacy of the LigB(131–645)/AH vaccine ranged from 87.5–100% and we observed sterile immunity (87.5–100%) among the vaccinated survivors. Significant levels of IgM and IgG were induced among vaccinated animals, although they did not correlate with immunity. A mixed IgG1/IgG2 subclass profile was associated with the subunit vaccine, compared to the predominant IgG2 profile seen in bacterin vaccinated hamsters. These findings suggest that LigB(131–645) is a vaccine candidate against leptospirosis with potential ramifications to public and veterinary health. Leptospirosis, also known as Weil’s disease, is spread by contact with infected animals or with water and soil containing pathogenic spirochaetes belonging to the Leptospira genus. Leptospirosis is a serious public health problem that can cause kidney failure, pulmonary complications and can be fatal. Due to its similarity to other tropical fevers, leptospirosis is difficult to diagnose. It occurs mainly in developing countries with tropical climates and the WHO considers it one of the most widespread zoonotic diseases in the world. Existing vaccines, known as bacterins, are not recommended for general use and cause serious side-effects. Advances in the field of leptospirosis research have identified leptospiral proteins for use in a recombinant vaccine. However, evaluations using animal models reported mixed success and this has raised doubts as to their usefulness. The current study reports, for the first time, the evaluation of a subunit vaccine that reproducibly protected hamsters against leptospirosis and that induced sterile immunity among survivors. Significant antibody levels were induced in vaccinated animals and the antibody profile was characterised and found to be different to that induced by a bacterin vaccine. These observations suggest that we have identified a potential vaccine candidate for human an animal leptospirosis.
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Grassmann AA, Souza JD, McBride AJA. A Universal Vaccine against Leptospirosis: Are We Going in the Right Direction? Front Immunol 2017; 8:256. [PMID: 28337203 PMCID: PMC5343615 DOI: 10.3389/fimmu.2017.00256] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 02/21/2017] [Indexed: 12/22/2022] Open
Abstract
Leptospirosis is the most widespread zoonosis in the world and a neglected tropical disease estimated to cause severe infection in more than one million people worldwide every year that can be combated by effective immunization. However, no significant progress has been made on the leptospirosis vaccine since the advent of bacterins over 100 years. Although protective against lethal infection, particularly in animals, bacterin-induced immunity is considered short term, serovar restricted, and the vaccine can cause serious side effects. The urgent need for a new vaccine has motivated several research groups to evaluate the protective immune response induced by recombinant vaccines. Significant protection has been reported with several promising outer membrane proteins, including LipL32 and the leptospiral immunoglobulin-like proteins. However, efficacy was variable and failed to induce a cross-protective response or sterile immunity among vaccinated animals. As hundreds of draft genomes of all known Leptospira species are now available, this should aid novel target discovery through reverse vaccinology (RV) and pangenomic studies. The identification of surface-exposed vaccine candidates that are highly conserved among infectious Leptospira spp. is a requirement for the development of a cross-protective universal vaccine. However, the lack of immune correlates is a major drawback to the application of RV to Leptospira genomes. In addition, as the protective immune response against leptospirosis is not fully understood, the rational use of adjuvants tends to be a process of trial and error. In this perspective, we discuss current advances, the pitfalls, and possible solutions for the development of a universal leptospirosis vaccine.
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Affiliation(s)
- André Alex Grassmann
- Biotechnology Unit, Technological Development Centre, Federal University of Pelotas , Pelotas , Brazil
| | - Jéssica Dias Souza
- Biotechnology Unit, Technological Development Centre, Federal University of Pelotas , Pelotas , Brazil
| | - Alan John Alexander McBride
- Biotechnology Unit, Technological Development Centre, Federal University of Pelotas, Pelotas, Brazil; Gonçalo Moniz Institute, Oswaldo Cruz Foundation, Ministry of Health, Salvador, Brazil
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Argondizzo APC, Rocha-de-Souza CM, de Almeida Santiago M, Galler R, Reis JN, Medeiros MA. Pneumococcal Predictive Proteins Selected by Microbial Genomic Approach Are Serotype Cross-Reactive and Bind to Host Extracellular Matrix Proteins. Appl Biochem Biotechnol 2017; 182:1518-1539. [PMID: 28211009 DOI: 10.1007/s12010-017-2415-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 01/16/2017] [Indexed: 11/30/2022]
Abstract
Streptococcus pneumoniae is a colonizer of the human nasopharynx, which accounts for most of the community-acquired pneumonia cases and can cause non-invasive and invasive diseases. Current available vaccines are serotype-specific and the use of recombinant proteins associated with virulence is an alternative to compose vaccines and to overcome these problems. In a previous work, we describe the identification of proteins in S. pneumoniae by reverse vaccinology and the genetic diversity of these proteins in clinical isolates. It was possible to purify a half of 20 selected proteins in soluble form. The expression of these proteins on the pneumococcal cells surface was confirmed by flow cytometry. We demonstrated that some of these proteins were able to bind to extracellular matrix proteins and were recognized by sera from patients with pneumococcal meningitis infection caused by several pneumococcal serotypes. In this context, our results suggest that these proteins may play a role in pneumococcal pathogenesis and might be considered as potential vaccine candidates.
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Affiliation(s)
- Ana Paula Corrêa Argondizzo
- Laboratory of Recombinant Technology, Bio-Manguinhos, Brazilian Health Ministry, FIOCRUZ, Rio de Janeiro, Brazil.
| | - Cláudio Marcos Rocha-de-Souza
- Research Laboratory of Hospital Infection, Collection Hospital Origin bacteria cultures, Instituto Oswaldo Cruz, Brazilian Health Ministry, FIOCRUZ, Rio de Janeiro, Brazil
| | - Marta de Almeida Santiago
- Laboratory of Diagnostic Technology, Bio-Manguinhos, Brazilian Health Ministry, FIOCRUZ, Rio de Janeiro, Brazil
| | - Ricardo Galler
- Fiocruz, Bio-Manguinhos, Brazilian Health Ministry, Rio de Janeiro, Brazil
| | - Joice Neves Reis
- School of Pharmacy, Federal University of Bahia, Salvador, BA, Brazil
| | - Marco Alberto Medeiros
- Laboratory of Recombinant Technology, Bio-Manguinhos, Brazilian Health Ministry, FIOCRUZ, Rio de Janeiro, Brazil
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21
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Hsieh CL, Chang E, Tseng A, Ptak C, Wu LC, Su CL, McDonough SP, Lin YP, Chang YF. Leptospira Immunoglobulin-Like Protein B (LigB) Binds to Both the C-Terminal 23 Amino Acids of Fibrinogen αC Domain and Factor XIII: Insight into the Mechanism of LigB-Mediated Blockage of Fibrinogen α Chain Cross-Linking. PLoS Negl Trop Dis 2016; 10:e0004974. [PMID: 27622634 PMCID: PMC5021285 DOI: 10.1371/journal.pntd.0004974] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 08/11/2016] [Indexed: 12/20/2022] Open
Abstract
The coagulation system provides a primitive but effective defense against hemorrhage. Soluble fibrinogen (Fg) monomers, composed of α, β and γ chains, are recruited to provide structural support for the formation of a hemostatic plug. Fg binds to platelets and is processed into a cross-linked fibrin polymer by the enzymatic clotting factors, thrombin and Factor XIII (FXIII). The newly formed fibrin-platelet clot can act as barrier to protect against pathogens from entering the bloodstream. Further, injuries caused by bacterial infections can be confined to the initial wound site. Many pathogenic bacteria have Fg-binding adhesins that can circumvent the coagulation pathway and allow the bacteria to sidestep containment. Fg expression is upregulated during lung infection providing an attachment surface for bacteria with the ability to produce Fg-binding adhesins. Fg binding by leptospira might play a crucial factor in Leptospira-associated pulmonary hemorrhage, the main factor contributing to lethality in severe cases of leptospirosis. The 12th domain of Leptospira immunoglobulin-like protein B (LigB12), a leptospiral adhesin, interacts with the C-terminus of FgαC (FgαCC). In this study, the binding site for LigB12 was mapped to the final 23 amino acids at the C-terminal end of FgαCC (FgαCC8). The association of FgαCC8 with LigB12 (ELISA, KD = 0.76 μM; SPR, KD = 0.96 μM) was reduced by mutations of both charged residues (R608, R611 and H614 from FgαCC8; D1061 from LigB12) and hydrophobic residues (I613 from FgαCC8; F1054 and A1065 from LigB12). Additionally, LigB12 bound strongly to FXIII and also inhibited fibrin formation, suggesting that LigB can disrupt coagulation by suppressing FXIII activity. Here, the detailed binding mechanism of a leptospiral adhesin to a host hemostatic factor is characterized for the first time and should provide better insight into the pathogenesis of leptospirosis. Leptospirosis, caused by pathogenic Leptospira spp., has been increasingly recognized as an emerging zoonosis worldwide. In human cases, clinical presentation can vary from a mild flu-like syndrome to severe multi-organ failure including hepatitis, nephritis and occasionally meningitis. Particularly, pulmonary hemorrhage has become one of the major factors leading to fatality. The host coagulation system normally can be activated to confine damage caused by bacteria. However, this spirochete has developed several virulence proteins to manipulate hemostatic factors including fibrinogen (Fg). Previously, we had observed that Leptospira immunoglobulin-like protein B (LigB) can bind to Fg and inhibit fibrin clot formation. In this study, the LigB binding site on fibrinogen was fine-mapped. The key amino acids contributing to this strong pathogen-host interaction were also identified. In addition, LigB bound to factor XIII and further interfered with the cross-linking of Fg. For the first time, a potential mechanism of leptospiral adhesin binding to fibrinogen was revealed, which should provide a better understanding of the pathogenesis of leptospirosis.
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Affiliation(s)
- Ching-Lin Hsieh
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Eric Chang
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Andrew Tseng
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Christopher Ptak
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Li-Chen Wu
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Chun-Li Su
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Sean P. McDonough
- Department of Biomedical Science, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Yi-Pin Lin
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, United States of America
| | - Yung-Fu Chang
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
- * E-mail:
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Fouts DE, Matthias MA, Adhikarla H, Adler B, Amorim-Santos L, Berg DE, Bulach D, Buschiazzo A, Chang YF, Galloway RL, Haake DA, Haft DH, Hartskeerl R, Ko AI, Levett PN, Matsunaga J, Mechaly AE, Monk JM, Nascimento ALT, Nelson KE, Palsson B, Peacock SJ, Picardeau M, Ricaldi JN, Thaipandungpanit J, Wunder EA, Yang XF, Zhang JJ, Vinetz JM. What Makes a Bacterial Species Pathogenic?:Comparative Genomic Analysis of the Genus Leptospira. PLoS Negl Trop Dis 2016; 10:e0004403. [PMID: 26890609 PMCID: PMC4758666 DOI: 10.1371/journal.pntd.0004403] [Citation(s) in RCA: 194] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 01/03/2016] [Indexed: 12/20/2022] Open
Abstract
Leptospirosis, caused by spirochetes of the genus Leptospira, is a globally widespread, neglected and emerging zoonotic disease. While whole genome analysis of individual pathogenic, intermediately pathogenic and saprophytic Leptospira species has been reported, comprehensive cross-species genomic comparison of all known species of infectious and non-infectious Leptospira, with the goal of identifying genes related to pathogenesis and mammalian host adaptation, remains a key gap in the field. Infectious Leptospira, comprised of pathogenic and intermediately pathogenic Leptospira, evolutionarily diverged from non-infectious, saprophytic Leptospira, as demonstrated by the following computational biology analyses: 1) the definitive taxonomy and evolutionary relatedness among all known Leptospira species; 2) genomically-predicted metabolic reconstructions that indicate novel adaptation of infectious Leptospira to mammals, including sialic acid biosynthesis, pathogen-specific porphyrin metabolism and the first-time demonstration of cobalamin (B12) autotrophy as a bacterial virulence factor; 3) CRISPR/Cas systems demonstrated only to be present in pathogenic Leptospira, suggesting a potential mechanism for this clade's refractoriness to gene targeting; 4) finding Leptospira pathogen-specific specialized protein secretion systems; 5) novel virulence-related genes/gene families such as the Virulence Modifying (VM) (PF07598 paralogs) proteins and pathogen-specific adhesins; 6) discovery of novel, pathogen-specific protein modification and secretion mechanisms including unique lipoprotein signal peptide motifs, Sec-independent twin arginine protein secretion motifs, and the absence of certain canonical signal recognition particle proteins from all Leptospira; and 7) and demonstration of infectious Leptospira-specific signal-responsive gene expression, motility and chemotaxis systems. By identifying large scale changes in infectious (pathogenic and intermediately pathogenic) vs. non-infectious Leptospira, this work provides new insights into the evolution of a genus of bacterial pathogens. This work will be a comprehensive roadmap for understanding leptospirosis pathogenesis. More generally, it provides new insights into mechanisms by which bacterial pathogens adapt to mammalian hosts.
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Affiliation(s)
- Derrick E. Fouts
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Michael A. Matthias
- Division of Infectious Diseases, Department of Medicine, University of California San Diego School of Medicine, La Jolla, California, United States of America
| | - Haritha Adhikarla
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Ben Adler
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Department of Microbiology, Monash University, Clayton, Australia
| | - Luciane Amorim-Santos
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
- Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz/MS, Salvador, Bahia, Brazil
| | - Douglas E. Berg
- Division of Infectious Diseases, Department of Medicine, University of California San Diego School of Medicine, La Jolla, California, United States of America
| | - Dieter Bulach
- Victorian Bioinformatics Consortium, Monash University, Clayton, Victoria, Australia
| | - Alejandro Buschiazzo
- Institut Pasteur de Montevideo, Laboratory of Molecular and Structural Microbiology, Montevideo, Uruguay
- Institut Pasteur, Department of Structural Biology and Chemistry, Paris, France
| | - Yung-Fu Chang
- Department of Population Medicine & Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Renee L. Galloway
- Centers for Disease Control and Prevention (DHHS, CDC, OID, NCEZID, DHCPP, BSPB), Atlanta, Georgia, United States of America
| | - David A. Haake
- VA Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
- David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
| | - Daniel H. Haft
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Rudy Hartskeerl
- WHO/FAO/OIE and National Collaborating Centre for Reference and Research on Leptospirosis, KIT Biomedical Research, Royal Tropical Institute (KIT), Amsterdam, The Netherlands
| | - Albert I. Ko
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
- Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz/MS, Salvador, Bahia, Brazil
| | - Paul N. Levett
- Government of Saskatchewan, Disease Control Laboratory Regina, Canada
| | - James Matsunaga
- VA Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
- David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
| | - Ariel E. Mechaly
- Institut Pasteur de Montevideo, Laboratory of Molecular and Structural Microbiology, Montevideo, Uruguay
| | - Jonathan M. Monk
- Department of Bioengineering, University of California, San Diego, La Jolla, California, United States of America
| | - Ana L. T. Nascimento
- Centro de Biotecnologia, Instituto Butantan, São Paulo, SP, Brazil
- Programa Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, USP, São Paulo, SP, Brazil
| | - Karen E. Nelson
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Bernhard Palsson
- Department of Bioengineering, University of California, San Diego, La Jolla, California, United States of America
| | - Sharon J. Peacock
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Mathieu Picardeau
- Institut Pasteur, Biology of Spirochetes Unit, National Reference Centre and WHO Collaborating Center for Leptospirosis, Paris, France
| | - Jessica N. Ricaldi
- Instituto de Medicina Tropical Alexander von Humboldt; Facultad de Medicina Alberto Hurtado, Universidd Peruana Cayetano Heredia, Lima, Peru
| | | | - Elsio A. Wunder
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
- Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz/MS, Salvador, Bahia, Brazil
| | - X. Frank Yang
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Jun-Jie Zhang
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Joseph M. Vinetz
- Division of Infectious Diseases, Department of Medicine, University of California San Diego School of Medicine, La Jolla, California, United States of America
- Instituto de Medicina Tropical Alexander von Humboldt; Facultad de Medicina Alberto Hurtado, Universidd Peruana Cayetano Heredia, Lima, Peru
- Instituto de Medicina “Alexander von Humboldt,” Universidad Peruana Cayetano Heredia, Lima, Peru
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Haake DA. The Miller Hypothesis. ACTA ACUST UNITED AC 2016; 7:167-174. [PMID: 30701122 DOI: 10.1615/forumimmundisther.2017020293] [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: 11/13/2022]
Abstract
The immune response is a cornerstone in the body's struggle against microbial pathogens. In ways that we do not yet completely understand, the mammalian immune response has evolved to identify proteins of pathogens that are either important virulence factors or key immunoprotective targets. Professor James N. Miller suggested that one way to discover such proteins is to harness the power of the immune system in the laboratory.This general concept, referred to here as the Miller Hypothesis, took several different manifestations in the discovery of some of the best known and widely studied leptospiral proteins: The porin OmpL1 was identified by surface immunoprecipitation, leptospiral immunoglobulin-like proteins were uncovered by screening a genomic library with sera from leptospirosis patients, and the major outer-membrane lipoprotein LipL32 was recognized through immunoblot studies. Such approaches will continue to bear fruit for both the leptospiral research field and research on other invasive pathogens.
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Affiliation(s)
- David A Haake
- Division of Infectious Diseases, 111F, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA 90073; and Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095; Tel.: 310-268-3814; ,
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24
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Fernandes LG, Siqueira GH, Teixeira ARF, Silva LP, Figueredo JM, Cosate MR, Vieira ML, Nascimento ALTO. Leptospira spp.: Novel insights into host-pathogen interactions. Vet Immunol Immunopathol 2015; 176:50-7. [PMID: 26727033 DOI: 10.1016/j.vetimm.2015.12.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 12/09/2015] [Accepted: 12/10/2015] [Indexed: 01/30/2023]
Abstract
Leptospirosis is a widespread zoonosis caused by pathogenic Leptospira spp. It is an important infectious disease that affects humans and animals. The disease causes economic losses as it affects livestock, with decreased milk production and death. Our group is investigating the genome sequences of L. interrogans targeting surface-exposed proteins because, due to their location, these proteins are capable to interact with several host components that could allow establishment of the infection. These interactions may involve adhesion of the bacteria to extracellular matrix (ECM) components and, hence, help bacterial colonization. The bacteria could also react with the host fibrinolytic system and/or with the coagulation cascade components, such as, plasminogen (PLG) and fibrinogen (Fg), respectively. The binding with the first system generates plasmin (PLA), increasing the proteolytic power of the bacteria, while the second interferes with clotting in a thrombin-catalyzed reaction, which may promote hemorrhage foci and increase bacterial dissemination. Interaction with the complement system negative regulators may help bacteria to evade the host immune system, facilitating the invasion. This work compiles the main described leptospiral proteins that could act as adhesins, as PLG and fibrinogen receptors and as complement regulator binding proteins. We present models in which we suggest possible mechanisms of how leptospires might colonize and invade host tissues, causing the disease. Understanding leptospiral pathogenesis will help to identify antigen candidates that would contribute to the development of more effective vaccines and diagnostic tests.
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Affiliation(s)
- Luis G Fernandes
- Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil; Programa de Pós Graduação Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, USP, Avenida Prof. Lineu Prestes, 1730, 05508-900, São Paulo, SP, Brazil
| | - Gabriela H Siqueira
- Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil; Programa de Pós Graduação Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, USP, Avenida Prof. Lineu Prestes, 1730, 05508-900, São Paulo, SP, Brazil
| | - Aline R F Teixeira
- Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil; Programa de Pós Graduação Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, USP, Avenida Prof. Lineu Prestes, 1730, 05508-900, São Paulo, SP, Brazil
| | - Lucas P Silva
- Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil; Programa de Pós Graduação Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, USP, Avenida Prof. Lineu Prestes, 1730, 05508-900, São Paulo, SP, Brazil
| | - Jupciana M Figueredo
- Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil; Programa de Pós Graduação Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, USP, Avenida Prof. Lineu Prestes, 1730, 05508-900, São Paulo, SP, Brazil
| | - Maria R Cosate
- Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil
| | - Monica L Vieira
- Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil
| | - Ana L T O Nascimento
- Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil; Programa de Pós Graduação Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, USP, Avenida Prof. Lineu Prestes, 1730, 05508-900, São Paulo, SP, Brazil.
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Pappas CJ, Picardeau M. Control of Gene Expression in Leptospira spp. by Transcription Activator-Like Effectors Demonstrates a Potential Role for LigA and LigB in Leptospira interrogans Virulence. Appl Environ Microbiol 2015; 81:7888-92. [PMID: 26341206 PMCID: PMC4616954 DOI: 10.1128/aem.02202-15] [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: 07/06/2015] [Accepted: 09/01/2015] [Indexed: 12/16/2022] Open
Abstract
Leptospirosis is a zoonotic disease that affects ∼1 million people annually, with a mortality rate of >10%. Currently, there is an absence of effective genetic manipulation tools for targeted mutagenesis in pathogenic leptospires. Transcription activator-like effectors (TALEs) are a recently described group of repressors that modify transcriptional activity in prokaryotic and eukaryotic cells by directly binding to a targeted sequence within the host genome. To determine the applicability of TALEs within Leptospira spp., two TALE constructs were designed. First, a constitutively expressed TALE gene specific for the lacO-like region upstream of bgaL was trans inserted in the saprophyte Leptospira biflexa (the TALEβgal strain). Reverse transcriptase PCR (RT-PCR) analysis and enzymatic assays demonstrated that BgaL was not expressed in the TALEβgal strain. Second, to study the role of LigA and LigB in pathogenesis, a constitutively expressed TALE gene with specificity for the homologous promoter regions of ligA and ligB was cis inserted into the pathogen Leptospira interrogans (TALElig). LigA and LigB expression was studied by using three independent clones: TALElig1, TALElig2, and TALElig3. Immunoblot analysis of osmotically induced TALElig clones demonstrated 2- to 9-fold reductions in the expression levels of LigA and LigB, with the highest reductions being noted for TALElig1 and TALElig2, which were avirulent in vivo and nonrecoverable from animal tissues. This study reconfirms galactosidase activity in the saprophyte and suggests a role for LigA and LigB in pathogenesis. Collectively, this study demonstrates that TALEs are effective at reducing the expression of targeted genes within saprophytic and pathogenic strains of Leptospira spp., providing an additional genetic manipulation tool for this genus.
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Affiliation(s)
- Christopher J Pappas
- Institut Pasteur, Unité de Biologie des Spirochètes, Paris, France Manhattanville College, Department of Biology, Purchase, New York, USA
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26
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Abstract
Pathogenic bacteria sense environmental cues, including the local temperature, to control the production of key virulence factors. Thermal regulation can be achieved at the level of DNA, RNA or protein and although many virulence factors are subject to thermal regulation, the exact mechanisms of control are yet to be elucidated in many instances. Understanding how virulence factors are regulated by temperature presents a significant challenge, as gene expression and protein production are often influenced by complex regulatory networks involving multiple transcription factors in bacteria. Here we highlight some recent insights into thermal regulation of virulence in pathogenic bacteria. We focus on bacteria which cause disease in mammalian hosts, which are at a significantly higher temperature than the outside environment. We outline the mechanisms of thermal regulation and how understanding this fundamental aspect of the biology of bacteria has implications for pathogenesis and human health.
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Affiliation(s)
- Oliver Lam
- a The Sir William Dunn School of Pathology ; University of Oxford ; Oxford , UK
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Evaluation of cell binding activities of Leptospira ECM adhesins. PLoS Negl Trop Dis 2015; 9:e0003712. [PMID: 25875373 PMCID: PMC4397020 DOI: 10.1371/journal.pntd.0003712] [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: 01/16/2015] [Accepted: 03/19/2015] [Indexed: 12/02/2022] Open
Abstract
Pathogenic spirochetes of the genus Leptospira are the causative agents of leptospirosis, a zoonotic infection that occurs globally. The bacteria colonize the renal proximal tubules of many animals and are shed in the urine. Contact with the urine, or with water contaminated with the urine of infected animals can cause infection of new host animals, including humans. Mechanisms of colonization of the proximal tubule and other tissues are not known, but specific interactions between bacterial adhesins and host substrates are likely to be critical in this process. Several extracellular matrix (ECM) adhesins have been previously identified, but more recently, it has been shown that Leptospira bind more efficiently to cells than ECM. In this work, recombinant forms of five putative Leptospira ECM adhesins, namely LipL32, Loa22, OmpL1, p31/LipL45, and LenA were evaluated for binding to cells as well as an expanded variety of ECM components. Reproducible and significant adhesin activity was demonstrated only for OmpL1, which bound to both mammalian cell lines tested and to glycosaminoglycans (GAGs). While determination of biologically significant bacterial adhesion activity will require generation of site-directed mutant strains, our results suggest that OmpL1 is a strong candidate for future evaluation regarding the roles of the adhesin activity of the protein during L. interrogans infection. Leptospirosis is the most widespread zoonotic infection in the world and represents a major public health problem, especially in tropical climates. The processes by which some Leptospira species cause infection, disease, and colonization of carrier animals remains poorly understood. Specific binding of Leptospira molecules and host molecules are likely important for infection and colonization. To identify Leptospira molecules that mediate attachment to host substrates, prior studies have evaluated Leptospira membrane proteins for binding to extracellular matrix (ECM) proteins. More recent data, however, show that Leptospira bind more efficiently to cells than to ECM. In search of adhesins mediating the latter activity, our study evaluated the direct cell binding activity of recombinant forms of a group of previously reported Leptospira ECM adhesins. Only one of these proteins, OmpL1, demonstrated reproducible direct cell binding activity. Further work will focus on identification of the mammalian receptor for OmpL1 and determining the biological significance of this activity during infection.
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Abstract
The outer membrane (OM) is the front line of leptospiral interactions with their environment and the mammalian host. Unlike most invasive spirochetes, pathogenic leptospires must be able to survive in both free-living and host-adapted states. As organisms move from one set of environmental conditions to another, the OM must cope with a series of conflicting challenges. For example, the OM must be porous enough to allow nutrient uptake, yet robust enough to defend the cell against noxious substances. In the host, the OM presents a surface decorated with adhesins and receptors for attaching to, and acquiring, desirable host molecules such as the complement regulator, Factor H.Factor H. On the other hand, the OM must enable leptospires to evade detection by the host's immune system on their way from sites of invasion through the bloodstream to the protected niche of the proximal tubule. The picture that is emerging of the leptospiral OM is that, while it shares many of the characteristics of the OMs of spirochetes and Gram-negative bacteria, it is also unique and different in ways that make it of general interest to microbiologists. For example, unlike most other pathogenic spirochetes, the leptospiral OM is rich in lipopolysaccharide (LPS). Leptospiral LPS is similar to that of Gram-negative bacteria but has a number of unique structural features that may explain why it is not recognized by the LPS-specific Toll-like receptor 4 of humans. As in other spirochetes, lipoproteins are major components of the leptospiral OM, though their roles are poorly understood. The functions of transmembrane outer membrane proteins (OMPs) in many cases are better understood, thanks to homologies with their Gram-negative counterparts and the emergence of improved genetic techniques. This chapter will review recent discoveries involving the leptospiral OM and its role in leptospiral physiology and pathogenesis.
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Affiliation(s)
- David A Haake
- Division of Infectious Diseases, VA Greater Los Angeles Healthcare System, Los Angeles, CA, 90073, USA,
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29
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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.
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30
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Abstract
Pathogenic Leptospira has the capacity to infect a broad range of mammalian hosts. Leptospirosis may appear as an acute, potentially fatal infection in accidental hosts, or progress into a chronic, largely asymptomatic infection in natural maintenance hosts. The course that Leptospira infection follows is dependent upon poorly understood factors, but is heavily influenced by both the host species and bacterial serovar involved in infection. Recognition of pathogen-associated molecular patterns (PAMPs) by a variety of host pattern recognition receptors (PRRs) activates the host immune system. The outcome of this response may result in bacterial clearance, limited bacterial colonization of a few target organs, principally the kidney, or induction of sepsis as the host succumbs to infection and dies. This chapter describes current knowledge of how the host recognizes Leptospira and responds to infection using innate and acquired immune responses. Aspects of immune-mediated pathology and pathogen strategies to evade the host immune response are also addressed.
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Affiliation(s)
- Richard L Zuerner
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University for Agricultural Sciences, 75007, Uppsala, Sweden,
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31
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Ptak CP, Hsieh CL, Lin YP, Maltsev AS, Raman R, Sharma Y, Oswald RE, Chang YF. NMR solution structure of the terminal immunoglobulin-like domain from the leptospira host-interacting outer membrane protein, LigB. Biochemistry 2014; 53:5249-60. [PMID: 25068811 PMCID: PMC4139157 DOI: 10.1021/bi500669u] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A number of surface proteins specific to pathogenic strains of Leptospira have been identified. The Lig protein family has shown promise as a marker in typing leptospiral isolates for pathogenesis and as an antigen in vaccines. We used NMR spectroscopy to solve the solution structure of the twelfth immunoglobulin-like (Ig-like) repeat domain from LigB (LigB-12). The fold is similar to that of other bacterial Ig-like domains and comprised mainly of β-strands that form a β-sandwich based on a Greek-key folding arrangement. Based on sequence analysis and conservation of structurally important residues, homology models for the other LigB Ig-like domains were generated. The set of LigB models illustrates the electrostatic differences between the domains as well as the possible interactions between neighboring domains. Understanding the structure of the extracellular portion of LigB and related proteins is important for developing diagnostic methods and new therapeutics directed toward leptospirosis.
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Affiliation(s)
- Christopher P Ptak
- Department of Population Medicine and Diagnostic Sciences and ‡Department of Molecular Medicine, College of Veterinary Medicine, Cornell University , Ithaca, New York 14853, United States
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32
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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]
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33
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Toma C, Murray GL, Nohara T, Mizuyama M, Koizumi N, Adler B, Suzuki T. Leptospiral outer membrane protein LMB216 is involved in enhancement of phagocytic uptake by macrophages. Cell Microbiol 2014; 16:1366-77. [DOI: 10.1111/cmi.12296] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 03/05/2014] [Accepted: 03/18/2014] [Indexed: 12/19/2022]
Affiliation(s)
- Claudia Toma
- Department of Molecular Bacteriology and Immunology; Graduate School of Medicine; University of the Ryukyus; Okinawa 903-0215 Japan
| | - Gerald L. Murray
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics; Department of Microbiology; Monash University; Clayton Vic. 3800 Australia
| | - Toshitsugu Nohara
- Department of Molecular Bacteriology and Immunology; Graduate School of Medicine; University of the Ryukyus; Okinawa 903-0215 Japan
| | - Masaru Mizuyama
- Department of Molecular Bacteriology and Immunology; Graduate School of Medicine; University of the Ryukyus; Okinawa 903-0215 Japan
| | - Nobuo Koizumi
- Department of Bacteriology I; National Institute of Infectious Diseases; Tokyo 162-8640 Japan
| | - Ben Adler
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics; Department of Microbiology; Monash University; Clayton Vic. 3800 Australia
| | - Toshihiko Suzuki
- Department of Molecular Bacteriology and Immunology; Graduate School of Medicine; University of the Ryukyus; Okinawa 903-0215 Japan
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Krajewski SS, Narberhaus F. Temperature-driven differential gene expression by RNA thermosensors. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:978-988. [PMID: 24657524 DOI: 10.1016/j.bbagrm.2014.03.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 02/28/2014] [Accepted: 03/14/2014] [Indexed: 12/20/2022]
Abstract
Many prokaryotic genes are organized in operons. Genes organized in such transcription units are co-transcribed into a polycistronic mRNA. Despite being clustered in a single mRNA, individual genes can be subjected to differential regulation, which is mainly achieved at the level of translation depending on initiation and elongation. Efficiency of translation initiation is primarily determined by the structural accessibility of the ribosome binding site (RBS). Structured cis-regulatory elements like RNA thermometers (RNATs) can contribute to differential regulation of individual genes within a polycistronic mRNA. RNATs are riboregulators that mediate temperature-responsive regulation of a downstream gene by modulating the accessibility of its RBS. At low temperature, the RBS is trapped by intra-molecular base pairing prohibiting translation initiation. The secondary structure melts with increasing temperature thus liberating the RBS. Here, we present an overview of different RNAT types and specifically highlight recently discovered RNATs. The main focus of this review is on RNAT-based differential control of polycistronic operons. Finally, we discuss the influence of temperature on other riboregulators and the potential of RNATs in synthetic RNA biology. This article is part of a Special Issue entitled: Riboswitches.
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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.
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36
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Hartwig DD, Bacelo KL, Oliveira PDD, Oliveira TL, Seixas FK, Amaral MG, Hartleben CP, McBride AJA, Dellagostin OA. Mannosylated LigANI produced in Pichia pastoris protects hamsters against leptospirosis. Curr Microbiol 2013; 68:524-30. [PMID: 24343176 DOI: 10.1007/s00284-013-0505-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 10/27/2013] [Indexed: 01/12/2023]
Abstract
The C-terminal region of the Leptospiral immunoglobulin-like A protein (LigA) contains six carboxy-terminal Ig-like repeat domains (LigANI). Subunit vaccine preparations based on recombinant LigANI produced in Escherichia coli, are promising vaccine candidates, albeit with variable efficacy. In the present study, LigANI was expressed in the methylotrophic yeast Pichia pastoris using a 12 L bioreactor to produce mannosylated LigANI (mLigANI) for use in a vaccine preparation against leptospirosis. Hamsters immunized with a mLigANI vaccine preparation produced a significant IgG antibody response (P < 0.001) and were protected (83.3 %; P < 0.001) against lethal challenge with 36× LD50 of a virulent strain of L. interrogans serovar Copenhageni. A vaccine preparation based on demannosylated mLigANI (nmLigANI) elicited an immune response in hamsters, but did not afford protection. The production of mLigANI in bioreactor by P. pastoris yielded ~50 mg L(-1) of recombinant protein. P. pastoris is a potential platform for the production of leptospiral antigens on an industrial scale. The results demonstrate that LigANI secreted by P. pastoris on mannosylated form (mLigANI) protect hamsters as subunit vaccine of L. interrogans lethal infection.
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Affiliation(s)
- Daiane D Hartwig
- Unidade de Biotecnologia, Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas, Pelotas, RS, Brazil,
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37
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Vieira ML, Fernandes LG, Domingos RF, Oliveira R, Siqueira GH, Souza NM, Teixeira ARF, Atzingen MV, Nascimento ALTO. Leptospiral extracellular matrix adhesins as mediators of pathogen-host interactions. FEMS Microbiol Lett 2013; 352:129-39. [PMID: 24289724 DOI: 10.1111/1574-6968.12349] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 11/19/2013] [Accepted: 11/26/2013] [Indexed: 01/21/2023] Open
Abstract
Leptospirosis is been considered an important infectious disease that affects humans and animals worldwide. This review summarizes our current knowledge of bacterial attachment to extracellular matrix (ECM) components and discusses the possible role of these interactions for leptospiral pathogenesis. Leptospiral proteins show different binding specificity for ECM molecules: some are exclusive laminin-binding proteins (Lsa24/LfhA/LenA, Lsa27), while others have broader spectrum binding profiles (LigB, Lsa21, LipL53). These proteins may play a primary role in the colonization of host tissues. Moreover, there are multifunctional proteins that exhibit binding activities toward a number of target proteins including plasminogen/plasmin and regulators of the complement system, and as such, might also act in bacterial dissemination and immune evasion processes. Many ECM-interacting proteins are recognized by human leptospirosis serum samples indicating their expression during infection. This compilation of data should enhance our understanding of the molecular mechanisms of leptospiral pathogenesis.
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Affiliation(s)
- Monica L Vieira
- Centro de Biotecnologia, Instituto Butantan, São Paulo, SP, Brazil
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Role for cis-acting RNA sequences in the temperature-dependent expression of the multiadhesive lig proteins in Leptospira interrogans. J Bacteriol 2013; 195:5092-101. [PMID: 24013626 DOI: 10.1128/jb.00663-13] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The spirochete Leptospira interrogans causes a systemic infection that provokes a febrile illness. The putative lipoproteins LigA and LigB promote adhesion of Leptospira to host proteins, interfere with coagulation, and capture complement regulators. In this study, we demonstrate that the expression level of the LigA and LigB proteins was substantially higher when L. interrogans proliferated at 37°C instead of the standard culture temperature of 30°C. The RNA comprising the 175-nucleotide 5' untranslated region (UTR) and first six lig codons, whose sequence is identical in ligA and ligB, is predicted to fold into two distinct stem-loop structures separated by a single-stranded region. The ribosome-binding site is partially sequestered in double-stranded RNA within the second structure. Toeprint analysis revealed that in vitro formation of a 30S-tRNA(fMet)-mRNA ternary complex was inhibited unless a 5' deletion mutation disrupted the second stem-loop structure. To determine whether the lig sequence could mediate temperature-regulated gene expression in vivo, the 5' UTR and the first six codons were inserted between the Escherichia coli l-arabinose promoter and bgaB (β-galactosidase from Bacillus stearothermophilus) to create a translational fusion. The lig fragment successfully conferred thermoregulation upon the β-galactosidase reporter in E. coli. The second stem-loop structure was sufficient to confer thermoregulation on the reporter, while sequences further upstream in the 5' UTR slightly diminished expression at each temperature tested. Finally, the expression level of β-galactosidase was significantly higher when point mutations predicted to disrupt base pairs in the second structure were introduced into the stem. Compensatory mutations that maintained base pairing of the stem without restoring the wild-type sequence reinstated the inhibitory effect of the 5' UTR on expression. These results indicate that ligA and ligB expression is limited by double-stranded RNA that occludes the ribosome-binding site. At elevated temperatures, the ribosome-binding site is exposed to promote translation initiation.
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39
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Oliveira R, Domingos RF, Siqueira GH, Fernandes LG, Souza NM, Vieira ML, de Morais ZM, Vasconcellos SA, Nascimento ALTO. Adhesins of Leptospira interrogans mediate the interaction to fibrinogen and inhibit fibrin clot formation in vitro. PLoS Negl Trop Dis 2013; 7:e2396. [PMID: 24009788 PMCID: PMC3757074 DOI: 10.1371/journal.pntd.0002396] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 07/19/2013] [Indexed: 12/31/2022] Open
Abstract
We report in this work that Leptospira strains, virulent L. interrogans serovar Copenhageni, attenuated L. interrogans serovar Copenhageni and saprophytic L. biflexa serovar Patoc are capable of binding fibrinogen (Fg). The interaction of leptospires with Fg inhibits thrombin- induced fibrin clot formation that may affect the haemostatic equilibrium. Additionally, we show that plasminogen (PLG)/plasmin (PLA) generation on the surface of Leptospira causes degradation of human Fg. The data suggest that PLA-coated leptospires were capable to employ their proteolytic activity to decrease one substrate of the coagulation cascade. We also present six leptospiral adhesins and PLG- interacting proteins, rLIC12238, Lsa33, Lsa30, OmpL1, rLIC11360 and rLIC11975, as novel Fg-binding proteins. The recombinant proteins interact with Fg in a dose-dependent and saturable fashion when increasing protein concentration was set to react to a fix human Fg concentration. The calculated dissociation equilibrium constants (KD) of these reactions ranged from 733.3±276.8 to 128±89.9 nM for rLIC12238 and Lsa33, respectively. The interaction of recombinant proteins with human Fg resulted in inhibition of fibrin clot by thrombin-catalyzed reaction, suggesting that these versatile proteins could mediate Fg interaction in Leptospira. Our data reveal for the first time the inhibition of fibrin clot by Leptospira spp. and presents adhesins that could mediate these interactions. Decreasing fibrin clot would cause an imbalance of the coagulation cascade that may facilitate bleeding and help bacteria dissemination Leptospirosis is probably the most widespread zoonosis in the world. Caused by spirochaetes of the genus Leptospira, it has greater incidence in tropical and subtropical regions. The disease has become prevalent in cities with sanitation problems and a large population of urban rodent reservoirs, which contaminate the environment through their urine. Understanding the mechanisms involved in pathogenesis of leptospirosis should contribute to new strategies that would help fight the disease. We show in this work that Leptospira strains, virulent, attenuated or saprophytic are capable of binding fibrinogen (Fg). The interaction of leptospires with Fg inhibits the formation of fibrin clot that may result of an imbalance in the haemostatic equilibrium. In addition, we show that plasminogen (PLG)/plasmin (PLA) generation on the surface of leptospires can lead to Fg degradation, showing evidence of possible route of fibrinolysis in leptospirosis. We also present six leptospiral proteins, as novel Fg-binding proteins, capable of inhibiting fibrin clot formation by thrombin-catalyzed reaction, suggesting that in Leptospira these multifunctional proteins could mediate Fg interaction. Our data suggest possible mechanisms that leptospires could employ to affect the coagulation cascade and fibrinolytic system that might lead to bacteria spreading.
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Affiliation(s)
- Rosane Oliveira
- Centro de Biotecnologia, Instituto Butantan, São Paulo, São Paulo, Brazil
- Programa Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Renan F. Domingos
- Centro de Biotecnologia, Instituto Butantan, São Paulo, São Paulo, Brazil
- Programa Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Gabriela H. Siqueira
- Centro de Biotecnologia, Instituto Butantan, São Paulo, São Paulo, Brazil
- Programa Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Luis G. Fernandes
- Centro de Biotecnologia, Instituto Butantan, São Paulo, São Paulo, Brazil
- Programa Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Natalie M. Souza
- Centro de Biotecnologia, Instituto Butantan, São Paulo, São Paulo, Brazil
- Programa Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Monica L. Vieira
- Centro de Biotecnologia, Instituto Butantan, São Paulo, São Paulo, Brazil
| | - Zenaide M. de Morais
- Laboratorio de Zoonoses Bacterianas do VPS, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, Brazil
| | - Silvio A. Vasconcellos
- Laboratorio de Zoonoses Bacterianas do VPS, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, Brazil
| | - Ana L. T. O. Nascimento
- Centro de Biotecnologia, Instituto Butantan, São Paulo, São Paulo, Brazil
- Programa Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
- * E-mail: .
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Kumar S, Puniya BL, Parween S, Nahar P, Ramachandran S. Identification of novel adhesins of M. tuberculosis H37Rv using integrated approach of multiple computational algorithms and experimental analysis. PLoS One 2013; 8:e69790. [PMID: 23922800 PMCID: PMC3726780 DOI: 10.1371/journal.pone.0069790] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 06/18/2013] [Indexed: 01/24/2023] Open
Abstract
Pathogenic bacteria interacting with eukaryotic host express adhesins on their surface. These adhesins aid in bacterial attachment to the host cell receptors during colonization. A few adhesins such as Heparin binding hemagglutinin adhesin (HBHA), Apa, Malate Synthase of M. tuberculosis have been identified using specific experimental interaction models based on the biological knowledge of the pathogen. In the present work, we carried out computational screening for adhesins of M. tuberculosis. We used an integrated computational approach using SPAAN for predicting adhesins, PSORTb, SubLoc and LocTree for extracellular localization, and BLAST for verifying non-similarity to human proteins. These steps are among the first of reverse vaccinology. Multiple claims and attacks from different algorithms were processed through argumentative approach. Additional filtration criteria included selection for proteins with low molecular weights and absence of literature reports. We examined binding potential of the selected proteins using an image based ELISA. The protein Rv2599 (membrane protein) binds to human fibronectin, laminin and collagen. Rv3717 (N-acetylmuramoyl-L-alanine amidase) and Rv0309 (L,D-transpeptidase) bind to fibronectin and laminin. We report Rv2599 (membrane protein), Rv0309 and Rv3717 as novel adhesins of M. tuberculosis H37Rv. Our results expand the number of known adhesins of M. tuberculosis and suggest their regulated expression in different stages.
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Affiliation(s)
- Sanjiv Kumar
- Functional Genomics Unit, Council of Scientific and Industrial Research -Institute of Genomics and Integrative Biology (CSIR-IGIB), New Delhi, India
| | - Bhanwar Lal Puniya
- Functional Genomics Unit, Council of Scientific and Industrial Research -Institute of Genomics and Integrative Biology (CSIR-IGIB), New Delhi, India
| | - Shahila Parween
- Functional Genomics Unit, Council of Scientific and Industrial Research -Institute of Genomics and Integrative Biology (CSIR-IGIB), New Delhi, India
| | - Pradip Nahar
- Functional Genomics Unit, Council of Scientific and Industrial Research -Institute of Genomics and Integrative Biology (CSIR-IGIB), New Delhi, India
| | - Srinivasan Ramachandran
- Functional Genomics Unit, Council of Scientific and Industrial Research -Institute of Genomics and Integrative Biology (CSIR-IGIB), New Delhi, India
- * E-mail:
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Nabity SA, Ribeiro GS, Lessa Aquino C, Takahashi D, Damião AO, Gonçalves AHO, Miranda-Filho DB, Greenwald R, Esfandiari J, Lyashchenko KP, Reis MG, Medeiros MA, Ko AI. Accuracy of a dual path platform (DPP) assay for the rapid point-of-care diagnosis of human leptospirosis. PLoS Negl Trop Dis 2012; 6:e1878. [PMID: 23133686 PMCID: PMC3486890 DOI: 10.1371/journal.pntd.0001878] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 09/10/2012] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Diagnosis of leptospirosis by the gold standard serologic assay, the microscopic agglutination test (MAT), requires paired sera and is not widely available. We developed a rapid assay using immunodominant Leptospira immunoglobulin-like (Lig) proteins in a Dual Path Platform (DPP). This study aimed to evaluate the assay's diagnostic performance in the setting of urban transmission. METHODOLOGY We determined test sensitivity using 446 acute and convalescent sera from MAT-confirmed case-patients with severe or mild leptospirosis in Brazil. We assessed test specificity using 677 sera from the following groups: healthy residents of a Brazilian slum with endemic transmission, febrile outpatients from the same slum, healthy blood donors, and patients with dengue, hepatitis A, and syphilis. Three operators independently interpreted visual results without knowing specimen status. RESULTS The overall sensitivity for paired sera was 100% and 73% for severe and mild disease, respectively. In the acute phase, the assay achieved a sensitivity of 85% and 64% for severe and mild leptospirosis, respectively. Within seven days of illness onset, the assay achieved a sensitivity of 77% for severe disease and 60% for mild leptospirosis. Sensitivity of the DPP assay was similar to that for IgM-ELISA and increased with both duration of symptoms (chi-square regression P = 0.002) and agglutinating titer (Spearman ρ = 0.24, P<0.001). Specificity was ≥93% for dengue, hepatitis A, syphilis, febrile outpatients, and blood donors, while it was 86% for healthy slum residents. Inter-operator agreement ranged from very good to excellent (kappa: 0.82-0.94) and test-to-test reproducibility was also high (kappa: 0.89). CONCLUSIONS The DPP assay performed acceptably well for diagnosis of severe acute clinical leptospirosis and can be easily implemented in hospitals and health posts where leptospirosis is a major public health problem. However, test accuracy may need improvement for mild disease and early stage leptospirosis, particularly in regions with high transmission.
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Affiliation(s)
- Scott A. Nabity
- Duke University School of Medicine, Durham, North Carolina, United States of America
- Centro de Pesquisa de Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil
| | - Guilherme S. Ribeiro
- Centro de Pesquisa de Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil
- Instituto de Saúde Coletiva, Universidade Federal da Bahia, Salvador, Brazil
| | | | - Daniele Takahashi
- Centro de Pesquisa de Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil
| | | | | | | | - Rena Greenwald
- Chembio Diagnostic Systems, Medford, New York, United States of America
| | - Javan Esfandiari
- Chembio Diagnostic Systems, Medford, New York, United States of America
| | | | - Mitermayer G. Reis
- Centro de Pesquisa de Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil
| | | | - Albert I. Ko
- Centro de Pesquisa de Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil
- Yale University Schools of Public Health and Medicine, New Haven, Connecticut, United States of America
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Leptospira and inflammation. Mediators Inflamm 2012; 2012:317950. [PMID: 23132959 PMCID: PMC3485547 DOI: 10.1155/2012/317950] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 09/25/2012] [Accepted: 09/27/2012] [Indexed: 12/21/2022] Open
Abstract
Leptospirosis is an important zoonosis and has a worldwide impact on public health. This paper will discuss both the role of immunogenic and pathogenic molecules during leptospirosis infection and possible new targets for immunotherapy against leptospira components. Leptospira, possess a wide variety of mechanisms that allow them to evade the host immune system and cause infection. Many molecules contribute to the ability of Leptospira to adhere, invade, and colonize. The recent sequencing of the Leptospira genome has increased our knowledge about this pathogen. Although the virulence factors, molecular targets, mechanisms of inflammation, and signaling pathways triggered by leptospiral antigens have been studied, some questions are still unanswered. Toll-like receptors (TLRs) are the primary sensors of invading pathogens. TLRs recognize conserved microbial pattern molecules and activate signaling pathways that are pivotal to innate and adaptive immune responses. Recently, a new molecular target has emerged—the Na/K-ATPase—which may contribute to inflammatory and metabolic alteration in this syndrome. Na/K-ATPase is a target for specific fatty acids of host origin and for bacterial components such as the glycolipoprotein fraction (GLP) that may lead to inflammasome activation. We propose that in addition to TLRs, Na/K-ATPase may play a role in the innate response to leptospirosis infection.
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Leptospiral outer membrane protein microarray, a novel approach to identification of host ligand-binding proteins. J Bacteriol 2012; 194:6074-87. [PMID: 22961849 DOI: 10.1128/jb.01119-12] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Leptospirosis is a zoonosis with worldwide distribution caused by pathogenic spirochetes belonging to the genus Leptospira. The leptospiral life cycle involves transmission via freshwater and colonization of the renal tubules of their reservoir hosts. Infection requires adherence to cell surfaces and extracellular matrix components of host tissues. These host-pathogen interactions involve outer membrane proteins (OMPs) expressed on the bacterial surface. In this study, we developed an Leptospira interrogans serovar Copenhageni strain Fiocruz L1-130 OMP microarray containing all predicted lipoproteins and transmembrane OMPs. A total of 401 leptospiral genes or their fragments were transcribed and translated in vitro and printed on nitrocellulose-coated glass slides. We investigated the potential of this protein microarray to screen for interactions between leptospiral OMPs and fibronectin (Fn). This approach resulted in the identification of the recently described fibronectin-binding protein, LIC10258 (MFn8, Lsa66), and 14 novel Fn-binding proteins, denoted Microarray Fn-binding proteins (MFns). We confirmed Fn binding of purified recombinant LIC11612 (MFn1), LIC10714 (MFn2), LIC11051 (MFn6), LIC11436 (MFn7), LIC10258 (MFn8, Lsa66), and LIC10537 (MFn9) by far-Western blot assays. Moreover, we obtained specific antibodies to MFn1, MFn7, MFn8 (Lsa66), and MFn9 and demonstrated that MFn1, MFn7, and MFn9 are expressed and surface exposed under in vitro growth conditions. Further, we demonstrated that MFn1, MFn4 (LIC12631, Sph2), and MFn7 enable leptospires to bind fibronectin when expressed in the saprophyte, Leptospira biflexa. Protein microarrays are valuable tools for high-throughput identification of novel host ligand-binding proteins that have the potential to play key roles in the virulence mechanisms of pathogens.
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Choy HA. Multiple activities of LigB potentiate virulence of Leptospira interrogans: inhibition of alternative and classical pathways of complement. PLoS One 2012; 7:e41566. [PMID: 22911815 PMCID: PMC3402383 DOI: 10.1371/journal.pone.0041566] [Citation(s) in RCA: 38] [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: 02/22/2012] [Accepted: 06/27/2012] [Indexed: 11/19/2022] Open
Abstract
Microbial pathogens acquire the immediate imperative to avoid or counteract the formidable defense of innate immunity as soon as they overcome the initial physical barriers of the host. Many have adopted the strategy of directly disrupting the complement system through the capture of its components, using proteins on the pathogen's surface. In leptospirosis, pathogenic Leptospira spp. are resistant to complement-mediated killing, in contrast to the highly vulnerable non-pathogenic strains. Pathogenic L. interrogans uses LenA/LfhA and LcpA to respectively sequester and commandeer the function of two regulators, factor H and C4BP, which in turn bind C3b or C4b to interrupt the alternative or classical pathways of complement activation. LigB, another surface-proximal protein originally characterized as an adhesin binding multiple host proteins, has other activities suggesting its importance early in infection, including binding extracellular matrix, plasma, and cutaneous repair proteins and inhibiting hemostasis. In this study, we used a recent model of ectopic expression of LigB in the saprophyte, L. biflexa, to test the hypothesis that LigB also interacts with complement proteins C3b and C4b to promote the virulence of L. interrogans. The surface expression of LigB partially rescued the non-pathogen from killing by 5% normal human serum, showing 1.3- to 48-fold greater survival 4 to 6 d following exposure to complement than cultures of the non-expressing parental strain. Recombinant LigB7'-12 comprising the LigB-specific immunoglobulin repeats binds directly to human complement proteins, C3b and C4b, with respective K(d)s of 43±26 nM and 69±18 nM. Repeats 9 to 11, previously shown to contain the binding domain for fibronectin and fibrinogen, are also important in LigB-complement interactions, which interfere with the alternative and classical pathways measured by complement-mediated hemolysis of erythrocytes. Thus, LigB is an adaptable interface for L. interrogans to efficiently counteract the multiple homeostatic processes of the host.
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Affiliation(s)
- Henry A Choy
- Department of Medicine, David Geffen School of Medicine at University of California Los Angeles (UCLA), Los Angeles, California, United States of America.
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Singh B, Fleury C, Jalalvand F, Riesbeck K. Human pathogens utilize host extracellular matrix proteins laminin and collagen for adhesion and invasion of the host. FEMS Microbiol Rev 2012; 36:1122-80. [PMID: 22537156 DOI: 10.1111/j.1574-6976.2012.00340.x] [Citation(s) in RCA: 199] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Revised: 02/08/2012] [Accepted: 03/29/2012] [Indexed: 01/11/2023] Open
Abstract
Laminin (Ln) and collagen are multifunctional glycoproteins that play an important role in cellular morphogenesis, cell signalling, tissue repair and cell migration. These proteins are ubiquitously present in tissues as a part of the basement membrane (BM), constitute a protective layer around blood capillaries and are included in the extracellular matrix (ECM). As a component of BMs, both Lns and collagen(s), thus function as major mechanical containment molecules that protect tissues from pathogens. Invasive pathogens breach the basal lamina and degrade ECM proteins of interstitial spaces and connective tissues using various ECM-degrading proteases or surface-bound plasminogen and matrix metalloproteinases recruited from the host. Most pathogens associated with the respiratory, gastrointestinal, or urogenital tracts, as well as with the central nervous system or the skin, have the capacity to bind and degrade Lns and collagen(s) in order to adhere to and invade host tissues. In this review, we focus on the adaptability of various pathogens to utilize these ECM proteins as enhancers for adhesion to host tissues or as a targets for degradation in order to breach the cellular barriers. The major pathogens discussed are Streptococcus, Staphylococcus, Pseudomonas, Salmonella, Yersinia, Treponema, Mycobacterium, Clostridium, Listeria, Porphyromonas and Haemophilus; Candida, Aspergillus, Pneumocystis, Cryptococcus and Coccidioides; Acanthamoeba, Trypanosoma and Trichomonas; retrovirus and papilloma virus.
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Affiliation(s)
- Birendra Singh
- Medical Microbiology, Department of Laboratory Medicine Malmö, Skåne University Hospital, Lund University, Malmö, Sweden
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Positive regulation of Leptospira interrogans kdp expression by KdpE as Demonstrated with a novel β-galactosidase reporter in Leptospira biflexa. Appl Environ Microbiol 2012; 78:5699-707. [PMID: 22685146 DOI: 10.1128/aem.00713-12] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Leptospirosis is a potentially deadly zoonotic disease that afflicts humans and animals. Leptospira interrogans, the predominant agent of leptospirosis, encounters diverse conditions as it proceeds through its life cycle, which includes stages inside and outside the host. Unfortunately, the number of genetic tools available for examining the regulation of gene expression in L. interrogans is limited. Consequently, little is known about the genetic circuits that control gene expression in Leptospira. To better understand the regulation of leptospiral gene expression, the L. interrogans kdp locus, encoding homologs of the P-type ATPase KdpABC potassium transporter with their KdpD sensors and KdpE response regulators, was selected for analysis. We showed that a kdpE mutation in L. interrogans prevented the increase in kdpABC mRNA levels observed in the wild-type L. interrogans strain when external potassium levels were low. To confirm that KdpE was a positive regulator of kdpABC transcription, we developed a novel approach for constructing chromosomal genetic fusions to the endogenous bgaL (β-galactosidase) gene of the nonpathogen Leptospira biflexa. We demonstrated positive regulation of a kdpA'-bgaL fusion in L. biflexa by the L. interrogans KdpE response regulator. A control lipL32'-bgaL fusion was not regulated by KdpE. These results demonstrate the utility of genetic fusions to the bgaL gene of L. biflexa for examining leptospiral gene regulation.
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Coutinho ML, Choy HA, Kelley MM, Matsunaga J, Babbitt JT, Lewis MS, Aleixo JAG, Haake DA. A LigA three-domain region protects hamsters from lethal infection by Leptospira interrogans. PLoS Negl Trop Dis 2011; 5:e1422. [PMID: 22180800 PMCID: PMC3236721 DOI: 10.1371/journal.pntd.0001422] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 10/23/2011] [Indexed: 11/19/2022] Open
Abstract
The leptospiral LigA protein consists of 13 bacterial immunoglobulin-like (Big) domains and is the only purified recombinant subunit vaccine that has been demonstrated to protect against lethal challenge by a clinical isolate of Leptospira interrogans in the hamster model of leptospirosis. We determined the minimum number and location of LigA domains required for immunoprotection. Immunization with domains 11 and 12 was found to be required but insufficient for protection. Inclusion of a third domain, either 10 or 13, was required for 100% survival after intraperitoneal challenge with Leptospira interrogans serovar Copenhageni strain Fiocruz L1-130. As in previous studies, survivors had renal colonization; here, we quantitated the leptospiral burden by qPCR to be 1.2×10(3) to 8×10(5) copies of leptospiral DNA per microgram of kidney DNA. Although renal histopathology in survivors revealed tubulointerstitial changes indicating an inflammatory response to the infection, blood chemistry analysis indicated that renal function was normal. These studies define the Big domains of LigA that account for its vaccine efficacy and highlight the need for additional strategies to achieve sterilizing immunity to protect the mammalian host from leptospiral infection and its consequences.
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Affiliation(s)
- Mariana L. Coutinho
- Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
- Centro de Desenvolvimento Tecnologico, Universidade Federal de Pelotas, Pelotas, Brasil
| | - Henry A. Choy
- Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
- Department of Medicine, David Geffen School of Medicine at University of California Los Angeles (UCLA), Los Angeles, California, United States of America
| | - Melissa M. Kelley
- Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
| | - James Matsunaga
- Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
- Department of Medicine, David Geffen School of Medicine at University of California Los Angeles (UCLA), Los Angeles, California, United States of America
| | - Jane T. Babbitt
- Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
- Department of Medicine, David Geffen School of Medicine at University of California Los Angeles (UCLA), Los Angeles, California, United States of America
| | - Michael S. Lewis
- Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
| | | | - David A. Haake
- Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
- Department of Medicine, David Geffen School of Medicine at University of California Los Angeles (UCLA), Los Angeles, California, United States of America
- Department of Urology, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
- Department of Microbiology, Immunology and Molecular Genetics, UCLA, Los Angeles, California, United States of America
- * E-mail:
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Dellagostin OA, Grassmann AA, Hartwig DD, Félix SR, da Silva ÉF, McBride AJA. Recombinant vaccines against leptospirosis. HUMAN VACCINES 2011; 7:1215-24. [PMID: 22048111 DOI: 10.4161/hv.7.11.17944] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Leptospirosis is an important neglected infectious disease that occurs in urban environments, as well as in rural regions worldwide. Rodents, the principal reservoir hosts of pathogenic Leptospira spp., and other infected animals shed the bacteria in their urine. During occupational or even recreational activities, humans that come into direct contact with infected animals or with a contaminated environment, particularly water, are at risk of infection. Prevention of urban leptospirosis is largely dependent on sanitation measures that are often difficult to implement, especially in developing countries. Vaccination with inactivated whole-cell preparations (bacterins) has limited efficacy due to the wide antigenic variation of the pathogen. Intensive efforts towards developing improved recombinant vaccines are ongoing. During the last decade, many reports on the evaluation of recombinant vaccines have been published. Partial success has been obtained with some surface-exposed protein antigens. The combination of protective antigens and new adjuvants or delivery systems may result in the much-needed effective vaccine.
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Affiliation(s)
- Odir A Dellagostin
- Unidade de Biotecnologia, Centro de Desenvolvimento Tecnológico, Salvador, BA, Brazil.
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Figueira CP, Croda J, Choy HA, Haake DA, Reis MG, Ko AI, Picardeau M. Heterologous expression of pathogen-specific genes ligA and ligB in the saprophyte Leptospira biflexa confers enhanced adhesion to cultured cells and fibronectin. BMC Microbiol 2011; 11:129. [PMID: 21658265 PMCID: PMC3133549 DOI: 10.1186/1471-2180-11-129] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 06/09/2011] [Indexed: 12/15/2022] Open
Abstract
Background In comparison to other bacterial pathogens, our knowledge of the molecular basis of the pathogenesis of leptospirosis is extremely limited. An improved understanding of leptospiral pathogenetic mechanisms requires reliable tools for functional genetic analysis. Leptospiral immunoglobulin-like (Lig) proteins are surface proteins found in pathogenic Leptospira, but not in saprophytes. Here, we describe a system for heterologous expression of the Leptospira interrogans genes ligA and ligB in the saprophyte Leptospira biflexa serovar Patoc. Results The genes encoding LigA and LigB under the control of a constitutive spirochaetal promoter were inserted into the L. biflexa replicative plasmid. We were able to demonstrate expression and surface localization of LigA and LigB in L. biflexa. We found that the expression of the lig genes significantly enhanced the ability of transformed L. biflexa to adhere in vitro to extracellular matrix components and cultured cells, suggesting the involvement of Lig proteins in cell adhesion. Conclusions This work reports a complete description of the system we have developed for heterologous expression of pathogen-specific proteins in the saprophytic L. biflexa. We show that expression of LigA and LigB proteins from the pathogen confers a virulence-associated phenotype on L. biflexa, namely adhesion to eukaryotic cells and fibronectin in vitro. This study indicates that L. biflexa can serve as a surrogate host to characterize the role of key virulence factors of the causative agent of leptospirosis.
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