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Moradkasani S, Maurin M, Farrokhi AS, Esmaeili S. Development, Strategies, and Challenges for Tularemia Vaccine. Curr Microbiol 2024; 81:126. [PMID: 38564047 DOI: 10.1007/s00284-024-03658-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 03/01/2024] [Indexed: 04/04/2024]
Abstract
Francisella tularensis is a facultative intracellular bacterial pathogen that affects both humans and animals. It was developed into a biological warfare weapon as a result. In this article, the current status of tularemia vaccine development is presented. A live-attenuated vaccine that was designed over 50 years ago using the less virulent F. tularensis subspecies holarctica is the only prophylactic currently available, but it has not been approved for use in humans or animals. Other promising live, killed, and subunit vaccine candidates have recently been developed and tested in animal models. This study will investigate some possible vaccines and the challenges they face during development.
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Affiliation(s)
- Safoura Moradkasani
- National Reference Laboratory for Plague, Tularemia and Q Fever, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Akanlu, KabudarAhang, Hamadan, Iran
- Department of Epidemiology and Biostatics, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Tehran, Iran
| | - Max Maurin
- CNRS, Grenoble INP, CHU Grenoble Alpes, TIMC-IMAG, Universite Grenoble Alpes, 38000, Grenoble, France
| | | | - Saber Esmaeili
- National Reference Laboratory for Plague, Tularemia and Q Fever, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Akanlu, KabudarAhang, Hamadan, Iran.
- Department of Epidemiology and Biostatics, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Tehran, Iran.
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Mlynek KD, Toothman RG, Martinez EE, Qiu J, Richardson JB, Bozue JA. Mutation of wbtJ, a N-formyltransferase involved in O-antigen synthesis, results in biofilm formation, phase variation and attenuation in Francisella tularensis. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001437. [PMID: 38421161 PMCID: PMC10924466 DOI: 10.1099/mic.0.001437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 01/29/2024] [Indexed: 03/02/2024]
Abstract
Two clinically important subspecies, Francisella tularensis subsp. tularensis (type A) and F. tularensis subsp. holarctica (type B) are responsible for most tularaemia cases, but these isolates typically form a weak biofilm under in vitro conditions. Phase variation of the F. tularensis lipopolysaccharide (LPS) has been reported in these subspecies, but the role of variation is unclear as LPS is crucial for virulence. We previously demonstrated that a subpopulation of LPS variants can constitutively form a robust biofilm in vitro, but it is unclear whether virulence was affected. In this study, we show that biofilm-forming variants of both fully virulent F. tularensis subspecies were highly attenuated in the murine tularaemia model by multiple challenge routes. Genomic sequencing was performed on these strains, which revealed that all biofilm-forming variants contained a lesion within the wbtJ gene, a formyltransferase involved in O-antigen synthesis. A ΔwbtJ deletion mutant recapitulated the biofilm, O-antigen and virulence phenotypes observed in natural variants and could be rescued through complementation with a functional wbtJ gene. Since the spontaneously derived biofilm-forming isolates in this study were a subpopulation of natural variants, reversion events to the wbtJ gene were detected that eliminated the phenotypes associated with biofilm variants and restored virulence. These results demonstrate a role for WbtJ in biofilm formation, LPS variation and virulence of F. tularensis.
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Affiliation(s)
- Kevin D. Mlynek
- Bacteriology Division, US ARMY Medical Research Institute of Infectious Diseases (USAMRIID), Frederick, MD, USA
| | - Ronald G. Toothman
- Bacteriology Division, US ARMY Medical Research Institute of Infectious Diseases (USAMRIID), Frederick, MD, USA
| | - Elsie E. Martinez
- Bacteriology Division, US ARMY Medical Research Institute of Infectious Diseases (USAMRIID), Frederick, MD, USA
| | - Ju Qiu
- Regulated Research Administration Division, USAMRIID, Frederick, MD, USA
| | | | - Joel A. Bozue
- Bacteriology Division, US ARMY Medical Research Institute of Infectious Diseases (USAMRIID), Frederick, MD, USA
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Bavlovic J, Pavkova I, Balonova L, Benada O, Stulik J, Klimentova J. Intact O-antigen is critical structure for the exceptional tubular shape of outer membrane vesicles in Francisella tularensis. Microbiol Res 2023; 269:127300. [PMID: 36641863 DOI: 10.1016/j.micres.2023.127300] [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: 05/24/2022] [Revised: 12/19/2022] [Accepted: 01/06/2023] [Indexed: 01/13/2023]
Abstract
Francisella tularensis is a highly infectious Gram-negative coccobacillus which causes the disease tularemia. The potential for its misuse as a biological weapon has led disease control and prevention centers to classify this bacterium as a category A agent. Bacterial outer membrane vesicles (OMVs) are spherical particles 20-250 nm in size produced by all Gram-negative bacteria and constitute one of the major secretory pathways. Bacteria use them in interacting with both other bacterial cells and eukaryotic (host) cells. OMVs of Francisella contain number of its so far described virulence factors and immunomodulatory proteins. Their role in host-pathogen interactions can therefore be presumed, and the possibility exists also for their potential use in a subunit vaccine. Moreover, Francisella microbes produce both usual spherical and unusual tubular OMVs. Because OMVs emerge from the outermost surface of the bacterial cell, we focused on the secretion of OMVs in several mutant Francisella strains with disrupted surface structures (namely the O-antigen). O-antigen in Francisella is not only the structural component of LPS but also forms another important virulence factor: the O-antigen polysaccharide capsule. Mutant strain phenotypes were evaluated by growth curves, vesiculation rates, their sensitivity to the complement contained in serum, and proliferation inside murine bone marrow macrophages. Morphologies of both OMVs and the bacteria were visualized by electron microscopy. The O-antigen mutant strains were considerably attenuated in serum resistance and intracellular proliferation. All the strains showed lower ability to form the tubular OMVs. Some strains formed tubular protrusions from their outer membrane but their stability was weak. Some hypervesiculating strains were revealed that will serve as source of OMVs for further studies of their protective potential. Our results suggest the presence of LPS and the O-antigen capsule on the surface of Francisella to be critical not only for its virulence but also for the exceptional tubular shape of its OMVs.
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Affiliation(s)
- Jan Bavlovic
- University of Defense, Faculty of Military Health Sciences, Department of Molecular Pathology and Biology, Třebešská 1575, 500 01 Hradec Králové, Czech Republic
| | - Ivona Pavkova
- University of Defense, Faculty of Military Health Sciences, Department of Molecular Pathology and Biology, Třebešská 1575, 500 01 Hradec Králové, Czech Republic
| | - Lucie Balonova
- University of Defense, Faculty of Military Health Sciences, Department of Molecular Pathology and Biology, Třebešská 1575, 500 01 Hradec Králové, Czech Republic
| | - Oldrich Benada
- Czech Academy of Sciences, Institute of Microbiology, Krč, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Jiri Stulik
- University of Defense, Faculty of Military Health Sciences, Department of Molecular Pathology and Biology, Třebešská 1575, 500 01 Hradec Králové, Czech Republic
| | - Jana Klimentova
- University of Defense, Faculty of Military Health Sciences, Department of Molecular Pathology and Biology, Třebešská 1575, 500 01 Hradec Králové, Czech Republic.
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Mlynek KD, Bozue JA. Why vary what's working? Phase variation and biofilm formation in Francisella tularensis. Front Microbiol 2022; 13:1076694. [PMID: 36560950 PMCID: PMC9763628 DOI: 10.3389/fmicb.2022.1076694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 11/17/2022] [Indexed: 12/12/2022] Open
Abstract
The notoriety of high-consequence human pathogens has increased in recent years and, rightfully, research efforts have focused on understanding host-pathogen interactions. Francisella tularensis has been detected in an impressively broad range of vertebrate hosts as well as numerous arthropod vectors and single-celled organisms. Two clinically important subspecies, F. tularensis subsp. tularensis (Type A) and F. tularensis subsp. holarctica (Type B), are responsible for the majority of tularemia cases in humans. The success of this bacterium in mammalian hosts can be at least partly attributed to a unique LPS molecule that allows the bacterium to avoid detection by the host immune system. Curiously, phase variation of the O-antigen incorporated into LPS has been documented in these subspecies of F. tularensis, and these variants often display some level of attenuation in infection models. While the role of phase variation in F. tularensis biology is unclear, it has been suggested that this phenomenon can aid in environmental survival and persistence. Biofilms have been established as the predominant lifestyle of many bacteria in the environment, though, it was previously thought that Type A and B isolates of F. tularensis typically form poor biofilms. Recent studies question this ideology as it was shown that alteration of the O-antigen allows robust biofilm formation in both Type A and B isolates. This review aims to explore the link between phase variation of the O-antigen, biofilm formation, and environmental persistence with an emphasis on clinically relevant subspecies and how understanding these poorly studied mechanisms could lead to new medical countermeasures to combat tularemia.
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Freudenberger Catanzaro KC, Lahmers KK, Allen IC, Inzana TJ. Alginate microencapsulation of an attenuated O-antigen mutant of Francisella tularensis LVS as a model for a vaccine delivery vehicle. PLoS One 2022; 17:e0259807. [PMID: 35275912 PMCID: PMC8916679 DOI: 10.1371/journal.pone.0259807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 02/23/2022] [Indexed: 11/23/2022] Open
Abstract
Francisella tularensis is the etiologic agent of tularemia and a Tier I Select Agent. Subspecies tularensis (Type A) is the most virulent of the four subspecies and inhalation of as few as 10 cells can cause severe disease in humans. Due to its niche as a facultative intracellular pathogen, a successful tularemia vaccine must induce a robust cellular immune response, which is best achieved by a live, attenuated strain. F. tularensis strains lacking lipopolysaccharide (LPS) O-antigen are highly attenuated, but do not persist in the host long enough to induce protective immunity. Increasing the persistence of an O-antigen mutant may help stimulate protective immunity. Alginate encapsulation is frequently used with probiotics to increase persistence of bacteria within the gastrointestinal system, and was used to encapsulate the highly attenuated LVS O-antigen mutant WbtIG191V. Encapsulation with alginate followed by a poly-L-lysine/alginate coating increased survival of WbtIG191V in complement-active serum. In addition, BALB/c mice immunized intraperitoneally with encapsulated WbtIG191V combined with purified LPS survived longer than mock-immunized mice following intranasal challenge. Alginate encapsulation of the bacteria also increased antibody titers compared to non-encapsulated bacteria. These data suggest that alginate encapsulation provides a slow-release vehicle for bacterial deposits, as evidenced by the increased antibody titer and increased persistence in serum compared to freely suspended cells. Survival of mice against high-dose intranasal challenge with the LVS wildtype was similar between mice immunized within alginate capsules or with LVS, possibly due to the low number of animals used, but bacterial loads in the liver and spleen were the lowest in mice immunized with WbtIG191V and LPS in beads. However, an analysis of the immune response of surviving mice indicated that those vaccinated with the alginate vehicle upregulated cell-mediated immune pathways to a lesser extent than LVS-vaccinated mice. In summary, this vehicle, as formulated, may be more effective for pathogens that require predominately antibody-mediated immunity.
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Affiliation(s)
- Kelly C. Freudenberger Catanzaro
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Kevin K. Lahmers
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Irving C. Allen
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Thomas J. Inzana
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, United States of America
- College of Veterinary Medicine, Long Island University, Brookville, New York, United States of America
- * E-mail:
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Modern Development and Production of a New Live Attenuated Bacterial Vaccine, SCHU S4 ΔclpB, to Prevent Tularemia. Pathogens 2021; 10:pathogens10070795. [PMID: 34201577 PMCID: PMC8308573 DOI: 10.3390/pathogens10070795] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/18/2021] [Accepted: 06/20/2021] [Indexed: 12/04/2022] Open
Abstract
Inhalation of small numbers of Francisella tularensis subspecies tularensis (Ftt) in the form of small particle aerosols causes severe morbidity and mortality in people and many animal species. For this reason, Ftt was developed into a bona fide biological weapon by the USA, by the former USSR, and their respective allies during the previous century. Although such weapons were never deployed, the 9/11 attack quickly followed by the Amerithrax attack led the U.S. government to seek novel countermeasures against a select group of pathogens, including Ftt. Between 2005–2009, we pursued a novel live vaccine against Ftt by deleting putative virulence genes from a fully virulent strain of the pathogen, SCHU S4. These mutants were screened in a mouse model, in which the vaccine candidates were first administered intradermally (ID) to determine their degree of attenuation. Subsequently, mice that survived a high dose ID inoculation were challenged by aerosol or intranasally (IN) with virulent strains of Ftt. We used the current unlicensed live vaccine strain (LVS), first discovered over 70 years ago, as a comparator in the same model. After screening 60 mutants, we found only one, SCHU S4 ΔclpB, that outperformed LVS in the mouse ID vaccination-respiratory-challenge model. Currently, SCHU S4 ΔclpB has been manufactured under current good manufacturing practice conditions, and tested for safety and efficacy in mice, rats, and macaques. The steps necessary for advancing SCHU S4 ΔclpB to this late stage of development are detailed herein. These include developing a body of data supporting the attenuation of SCHU S4 ΔclpB to a degree sufficient for removal from the U.S. Select Agent list and for human use; optimizing SCHU S4 ΔclpB vaccine production, scale up, and long-term storage; and developing appropriate quality control testing approaches.
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Golovliov I, Bäckman S, Granberg M, Salomonsson E, Lundmark E, Näslund J, Busch JD, Birdsell D, Sahl JW, Wagner DM, Johansson A, Forsman M, Thelaus J. Long-Term Survival of Virulent Tularemia Pathogens outside a Host in Conditions That Mimic Natural Aquatic Environments. Appl Environ Microbiol 2021; 87:e02713-20. [PMID: 33397692 PMCID: PMC8104992 DOI: 10.1128/aem.02713-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 12/17/2020] [Indexed: 01/22/2023] Open
Abstract
Francisella tularensis, the causative agent of the zoonotic disease tularemia, can cause seasonal outbreaks of acute febrile illness in humans with disease peaks in late summer to autumn. Interestingly, its mechanisms for environmental persistence between outbreaks are poorly understood. One hypothesis is that F. tularensis forms biofilms in aquatic environments. We utilized two fully virulent wild-type strains: FSC200 (Francisella tularensis subsp. holarctica) and Schu S4 (Francisella tularensis subsp. tularensis) and three control strains, the attenuated live vaccine strain (LVS; F. tularensis subsp. holarctica), a Schu S4 ΔwbtI mutant that is documented to form biofilms, and the low-virulence strain U112 of the closely related species Francisella novicida Strains were incubated in saline solution (0.9% NaCl) microcosms for 24 weeks at both 4°C and 20°C, whereupon viability and biofilm formation were measured. These temperatures were selected to approximate winter and summer temperatures of fresh water in Scandinavia, respectively. U112 and Schu S4 ΔwbtI formed biofilms, but F. tularensis strains FSC200 and Schu S4 and the LVS did not. All strains exhibited prolonged viability at 4°C compared to 20°C. U112 and FSC200 displayed remarkable long-term persistence at 4°C, with only 1- and 2-fold log reductions, respectively, of viable cells after 24 weeks. Schu S4 exhibited lower survival, yielding no viable cells by week 20. At 24 weeks, cells from FSC200, but not from Schu S4, were still fully virulent in mice. Taken together, these results demonstrate biofilm-independent, long-term survival of pathogenic F. tularensis subsp. holarctica in conditions that mimic overwinter survival in aquatic environments.IMPORTANCE Tularemia, a disease caused by the environmental bacterium Francisella tularensis, is characterized by acute febrile illness. F. tularensis is highly infectious: as few as 10 organisms can cause human disease. Tularemia is not known to be spread from person to person. Rather, all human infections are independently acquired from the environment via the bite of blood-feeding arthropods, ingestion of infected food or water, or inhalation of aerosolized bacteria. Despite the environmental origins of human disease events, the ecological factors governing the long-term persistence of F. tularensis in nature between seasonal human outbreaks are poorly understood. The significance of our research is in identifying conditions that promote long-term survival of fully virulent F. tularensis outside a mammalian host or insect vector. These conditions are similar to those found in natural aquatic environments in winter and provide important new insights on how F. tularensis may persist long-term in the environment.
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Affiliation(s)
- Igor Golovliov
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden
- Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - Stina Bäckman
- Division of CBRN Defence and Security, Swedish Defence Research Agency FOI, Umeå, Sweden
| | - Malin Granberg
- Division of CBRN Defence and Security, Swedish Defence Research Agency FOI, Umeå, Sweden
| | - Emelie Salomonsson
- Division of CBRN Defence and Security, Swedish Defence Research Agency FOI, Umeå, Sweden
| | - Eva Lundmark
- Division of CBRN Defence and Security, Swedish Defence Research Agency FOI, Umeå, Sweden
| | - Jonas Näslund
- Division of CBRN Defence and Security, Swedish Defence Research Agency FOI, Umeå, Sweden
| | - Joseph D Busch
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, USA
| | - Dawn Birdsell
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, USA
| | - Jason W Sahl
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, USA
| | - David M Wagner
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, USA
| | - Anders Johansson
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden
- Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - Mats Forsman
- Division of CBRN Defence and Security, Swedish Defence Research Agency FOI, Umeå, Sweden
| | - Johanna Thelaus
- Division of CBRN Defence and Security, Swedish Defence Research Agency FOI, Umeå, Sweden
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Freudenberger Catanzaro KC, Inzana TJ. The Francisella tularensis Polysaccharides: What Is the Real Capsule? Microbiol Mol Biol Rev 2020; 84:e00065-19. [PMID: 32051235 PMCID: PMC7018499 DOI: 10.1128/mmbr.00065-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Francisella tularensis is a tier 1 select agent responsible for tularemia in humans and a wide variety of animal species. Extensive research into understanding the virulence factors of the bacterium has been ongoing to develop an efficacious vaccine. At least two such virulence factors are described as capsules of F. tularensis: the O-antigen capsule and the capsule-like complex (CLC). These two separate entities aid in avoiding host immune defenses but have not been clearly differentiated. These components are distinct and differ in composition and genetic basis. The O-antigen capsule consists of a polysaccharide nearly identical to the lipopolysaccharide (LPS) O antigen, whereas the CLC is a heterogeneous complex of glycoproteins, proteins, and possibly outer membrane vesicles and tubes (OMV/Ts). In this review, the current understanding of these two capsules is summarized, and the historical references to "capsules" of F. tularensis are clarified. A significant amount of research has been invested into the composition of each capsule and the genes involved in synthesis of the polysaccharide portion of each capsule. Areas of future research include further exploration into the molecular regulation and pathways responsible for expression of each capsule and further elucidating the role that each capsule plays in virulence.
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Affiliation(s)
- Kelly C Freudenberger Catanzaro
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA
| | - Thomas J Inzana
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA
- Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA
- College of Veterinary Medicine, Long Island University, Brookville, New York, USA
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Stojkova P, Spidlova P, Lenco J, Rehulkova H, Kratka L, Stulik J. HU protein is involved in intracellular growth and full virulence of Francisella tularensis. Virulence 2018; 9:754-770. [PMID: 29473442 PMCID: PMC5955460 DOI: 10.1080/21505594.2018.1441588] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 01/18/2018] [Accepted: 02/13/2018] [Indexed: 12/23/2022] Open
Abstract
The nucleoid-associated HU proteins are small abundant DNA-binding proteins in bacterial cell which play an important role in the initiation of DNA replication, cell division, SOS response, control of gene expression and recombination. HU proteins bind to double stranded DNA non-specifically, but they exhibit high affinity to abnormal DNA structures as four-way junctions, gaps or nicks, which are generated during DNA damage. In many pathogens HU proteins regulate expression of genes involved in metabolism and virulence. Here, we show that the Francisella tularensis subsp. holarctica gene locus FTS_0886 codes for functional HU protein which is essential for full Francisella virulence and its resistance to oxidative stress. Further, our results demonstrate that the recombinant FtHU protein binds to double stranded DNA and protects it against free hydroxyl radicals generated via Fenton's reaction. Eventually, using an iTRAQ approach we identified proteins levels of which are affected by the deletion of hupB, among them for example Francisella pathogenicity island (FPI) proteins. The pleiotropic role of HU protein classifies it as a potential target for the development of therapeutics against tularemia.
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Affiliation(s)
- Pavla Stojkova
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - Petra Spidlova
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - Juraj Lenco
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - Helena Rehulkova
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - Lucie Kratka
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - Jiri Stulik
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
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Holland KM, Rosa SJ, Kristjansdottir K, Wolfgeher D, Franz BJ, Zarrella TM, Kumar S, Sunagar R, Singh A, Bakshi CS, Namjoshi P, Barry EM, Sellati TJ, Kron SJ, Gosselin EJ, Reed DS, Hazlett KRO. Differential Growth of Francisella tularensis, Which Alters Expression of Virulence Factors, Dominant Antigens, and Surface-Carbohydrate Synthases, Governs the Apparent Virulence of Ft SchuS4 to Immunized Animals. Front Microbiol 2017; 8:1158. [PMID: 28690600 PMCID: PMC5479911 DOI: 10.3389/fmicb.2017.01158] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 06/07/2017] [Indexed: 12/29/2022] Open
Abstract
The gram-negative bacterium Francisella tularensis (Ft) is both a potential biological weapon and a naturally occurring microbe that survives in arthropods, fresh water amoeba, and mammals with distinct phenotypes in various environments. Previously, we used a number of measurements to characterize Ft grown in Brain-Heart Infusion (BHI) broth as (1) more similar to infection-derived bacteria, and (2) slightly more virulent in naïve animals, compared to Ft grown in Mueller Hinton Broth (MHB). In these studies we observed that the free amino acids in MHB repress expression of select Ft virulence factors by an unknown mechanism. Here, we tested the hypotheses that Ft grown in BHI (BHI-Ft) accurately displays a full protein composition more similar to that reported for infection-derived Ft and that this similarity would make BHI-Ft more susceptible to pre-existing, vaccine-induced immunity than MHB-Ft. We performed comprehensive proteomic analysis of Ft grown in MHB, BHI, and BHI supplemented with casamino acids (BCA) and compared our findings to published “omics” data derived from Ft grown in vivo. Based on the abundance of ~1,000 proteins, the fingerprint of BHI-Ft is one of nutrient-deprived bacteria that—through induction of a stringent-starvation-like response—have induced the FevR regulon for expression of the bacterium's virulence factors, immuno-dominant antigens, and surface-carbohydrate synthases. To test the notion that increased abundance of dominant antigens expressed by BHI-Ft would render these bacteria more susceptible to pre-existing, vaccine-induced immunity, we employed a battery of LVS-vaccination and S4-challenge protocols using MHB- and BHI-grown Ft S4. Contrary to our hypothesis, these experiments reveal that LVS-immunization provides a barrier to infection that is significantly more effective against an MHB-S4 challenge than a BHI-S4 challenge. The differences in apparent virulence to immunized mice are profoundly greater than those observed with primary infection of naïve mice. Our findings suggest that tularemia vaccination studies should be critically evaluated in regard to the growth conditions of the challenge agent.
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Affiliation(s)
- Kristen M Holland
- Department of Immunology and Microbial Disease, Albany Medical CollegeAlbany, NY, United States
| | - Sarah J Rosa
- Department of Immunology and Microbial Disease, Albany Medical CollegeAlbany, NY, United States
| | | | - Donald Wolfgeher
- Department of Molecular Genetics and Cell Biology, University of ChicagoChicago, IL, United States
| | - Brian J Franz
- Department of Immunology and Microbial Disease, Albany Medical CollegeAlbany, NY, United States
| | - Tiffany M Zarrella
- Department of Immunology and Microbial Disease, Albany Medical CollegeAlbany, NY, United States
| | - Sudeep Kumar
- Department of Immunology and Microbial Disease, Albany Medical CollegeAlbany, NY, United States
| | - Raju Sunagar
- Department of Immunology and Microbial Disease, Albany Medical CollegeAlbany, NY, United States
| | - Anju Singh
- Trudeau InstituteSaranac Lake, NY, United States
| | - Chandra S Bakshi
- Department of Microbiology and Immunology, New York Medical CollegeValhalla, NY, United States
| | - Prachi Namjoshi
- Department of Immunology and Microbial Disease, Albany Medical CollegeAlbany, NY, United States
| | - Eileen M Barry
- School of Medicine, University of MarylandBaltimore, MD, United States
| | | | - Stephen J Kron
- Department of Molecular Genetics and Cell Biology, University of ChicagoChicago, IL, United States
| | - Edmund J Gosselin
- Department of Immunology and Microbial Disease, Albany Medical CollegeAlbany, NY, United States
| | - Douglas S Reed
- Center for Vaccine Research, University of PittsburghPittsburgh, PA, United States
| | - Karsten R O Hazlett
- Department of Immunology and Microbial Disease, Albany Medical CollegeAlbany, NY, United States
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Li H, Debowski AW, Liao T, Tang H, Nilsson HO, Marshall BJ, Stubbs KA, Benghezal M. Understanding protein glycosylation pathways in bacteria. Future Microbiol 2016; 12:59-72. [PMID: 27689684 DOI: 10.2217/fmb-2016-0166] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Through advances in analytical methods to detect glycoproteins and to determine glycan structures, there have been increasing reports of protein glycosylation in bacteria. In this review, we summarize the known pathways for bacterial protein glycosylation: lipid carrier-mediated 'en bloc' glycosylation; and cytoplasmic stepwise protein glycosylation. The exploitation of bacterial protein glycosylation systems, especially the 'mix and match' of three independent but similar pathways (oligosaccharyltransferase-mediated protein glycosylation, lipopolysaccharide and peptidoglycan biosynthesis) in Gram-negative bacteria for glycoengineering recombinant glycoproteins is also discussed.
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Affiliation(s)
- Hong Li
- West China Marshall Research Centre for Infectious Diseases, Centre of Infectious Diseases, West China Hospital of Sichuan University, Chengdu 610041, China.,Helicobacter Pylori Research Laboratory, School of Pathology & Laboratory Medicine, Marshall Centre for Infectious Disease Research & Training, The University of Western Australia, M504, L Block, QEII Medical Centre, Nedlands, WA 6009, Australia
| | - Aleksandra W Debowski
- Helicobacter Pylori Research Laboratory, School of Pathology & Laboratory Medicine, Marshall Centre for Infectious Disease Research & Training, The University of Western Australia, M504, L Block, QEII Medical Centre, Nedlands, WA 6009, Australia.,School of Chemistry & Biochemistry, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Tingting Liao
- Helicobacter Pylori Research Laboratory, School of Pathology & Laboratory Medicine, Marshall Centre for Infectious Disease Research & Training, The University of Western Australia, M504, L Block, QEII Medical Centre, Nedlands, WA 6009, Australia
| | - Hong Tang
- West China Marshall Research Centre for Infectious Diseases, Centre of Infectious Diseases, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Hans-Olof Nilsson
- Ondek Pty Ltd, School of Pathology & Laboratory Medicine, Marshall Centre for Infectious Disease Research & Training, The University of Western Australia, M504, L Block, QEII Medical Centre, Nedlands, WA 6009, Australia
| | - Barry J Marshall
- Helicobacter Pylori Research Laboratory, School of Pathology & Laboratory Medicine, Marshall Centre for Infectious Disease Research & Training, The University of Western Australia, M504, L Block, QEII Medical Centre, Nedlands, WA 6009, Australia
| | - Keith A Stubbs
- School of Chemistry & Biochemistry, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Mohammed Benghezal
- Helicobacter Pylori Research Laboratory, School of Pathology & Laboratory Medicine, Marshall Centre for Infectious Disease Research & Training, The University of Western Australia, M504, L Block, QEII Medical Centre, Nedlands, WA 6009, Australia.,Swiss Vitamin Institute, Route de la Corniche 1, CH-1066 Epalinges, Switzerland
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12
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Wu X, Ren G, Gunning WT, Weaver DA, Kalinoski AL, Khuder SA, Huntley JF. FmvB: A Francisella tularensis Magnesium-Responsive Outer Membrane Protein that Plays a Role in Virulence. PLoS One 2016; 11:e0160977. [PMID: 27513341 PMCID: PMC4981453 DOI: 10.1371/journal.pone.0160977] [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: 04/20/2016] [Accepted: 07/26/2016] [Indexed: 02/06/2023] Open
Abstract
Francisella tularensis is the causative agent of the lethal disease tularemia. Despite decades of research, little is understood about why F. tularensis is so virulent. Bacterial outer membrane proteins (OMPs) are involved in various virulence processes, including protein secretion, host cell attachment, and intracellular survival. Many pathogenic bacteria require metals for intracellular survival and OMPs often play important roles in metal uptake. Previous studies identified three F. tularensis OMPs that play roles in iron acquisition. In this study, we examined two previously uncharacterized proteins, FTT0267 (named fmvA, for Francisellametal and virulence) and FTT0602c (fmvB), which are homologs of the previously studied F. tularensis iron acquisition genes and are predicted OMPs. To study the potential roles of FmvA and FmvB in metal acquisition and virulence, we first examined fmvA and fmvB expression following pulmonary infection of mice, finding that fmvB was upregulated up to 5-fold during F. tularensis infection of mice. Despite sequence homology to previously-characterized iron-acquisition genes, FmvA and FmvB do not appear to be involved iron uptake, as neither fmvA nor fmvB were upregulated in iron-limiting media and neither ΔfmvA nor ΔfmvB exhibited growth defects in iron limitation. However, when other metals were examined in this study, magnesium-limitation significantly induced fmvB expression, ΔfmvB was found to express significantly higher levels of lipopolysaccharide (LPS) in magnesium-limiting medium, and increased numbers of surface protrusions were observed on ΔfmvB in magnesium-limiting medium, compared to wild-type F. tularensis grown in magnesium-limiting medium. RNA sequencing analysis of ΔfmvB revealed the potential mechanism for increased LPS expression, as LPS synthesis genes kdtA and wbtA were significantly upregulated in ΔfmvB, compared with wild-type F. tularensis. To provide further evidence for the potential role of FmvB in magnesium uptake, we demonstrated that FmvB was outer membrane-localized. Finally, ΔfmvB was found to be attenuated in mice and cytokine analyses revealed that ΔfmvB-infected mice produced lower levels of pro-inflammatory cytokines, including GM-CSF, IL-3, and IL-10, compared with mice infected with wild-type F. tularensis. Taken together, although the function of FmvA remains unknown, FmvB appears to play a role in magnesium uptake and F. tularensis virulence. These results may provide new insights into the importance of magnesium for intracellular pathogens.
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Affiliation(s)
- Xiaojun Wu
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States of America
| | - Guoping Ren
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States of America
| | - William T. Gunning
- Department of Pathology and Electron Microscopy Facility, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States of America
| | - David A. Weaver
- Department of Surgery and Advanced Microscopy and Imaging Center, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States of America
| | - Andrea L. Kalinoski
- Department of Surgery and Advanced Microscopy and Imaging Center, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States of America
| | - Sadik A. Khuder
- Department of Medicine, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States of America
| | - Jason F. Huntley
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States of America
- * E-mail:
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13
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Dankova V, Balonova L, Link M, Straskova A, Sheshko V, Stulik J. Inactivation of Francisella tularensis Gene Encoding Putative ABC Transporter Has a Pleiotropic Effect upon Production of Various Glycoconjugates. J Proteome Res 2016; 15:510-24. [DOI: 10.1021/acs.jproteome.5b00864] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Vera Dankova
- Department
of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove 500 01, Czech Republic
| | - Lucie Balonova
- Department
of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove 500 01, Czech Republic
| | - Marek Link
- Department
of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove 500 01, Czech Republic
| | - Adela Straskova
- Department
of Phototrophic Microorganisms, Institute of Microbiology, The Academy of Sciences of The Czech Republic, Trebon 379 81, Czech Republic
| | - Valeria Sheshko
- Department
of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove 500 01, Czech Republic
| | - Jiri Stulik
- Department
of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove 500 01, Czech Republic
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14
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Rowe HM, Huntley JF. From the Outside-In: The Francisella tularensis Envelope and Virulence. Front Cell Infect Microbiol 2015; 5:94. [PMID: 26779445 PMCID: PMC4688374 DOI: 10.3389/fcimb.2015.00094] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 12/07/2015] [Indexed: 12/20/2022] Open
Abstract
Francisella tularensis is a highly-infectious bacterium that causes the rapid, and often lethal disease, tularemia. Many studies have been performed to identify and characterize the virulence factors that F. tularensis uses to infect a wide variety of hosts and host cell types, evade immune defenses, and induce severe disease and death. This review focuses on the virulence factors that are present in the F. tularensis envelope, including capsule, LPS, outer membrane, periplasm, inner membrane, secretion systems, and various molecules in each of aforementioned sub-compartments. Whereas, no single bacterial molecule or molecular complex single-handedly controls F. tularensis virulence, we review here how diverse bacterial systems work in conjunction to subvert the immune system, attach to and invade host cells, alter phagosome/lysosome maturation pathways, replicate in host cells without being detected, inhibit apoptosis, and induce host cell death for bacterial release and infection of adjacent cells. Given that the F. tularensis envelope is the outermost layer of the bacterium, we highlight herein how many of these molecules directly interact with the host to promote infection and disease. These and future envelope studies are important to advance our collective understanding of F. tularensis virulence mechanisms and offer targets for future vaccine development efforts.
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Affiliation(s)
- Hannah M Rowe
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences Toledo, OH, USA
| | - Jason F Huntley
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences Toledo, OH, USA
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15
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Sigida EN, Fedonenko YP, Shashkov AS, Zdorovenko EL, Konnova SA, Ignatov VV, Knirel YA. Structural studies of the O-specific polysaccharide(s) from the lipopolysaccharide of Azospirillum brasilense type strain Sp7. Carbohydr Res 2013; 380:76-80. [DOI: 10.1016/j.carres.2013.07.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 07/25/2013] [Accepted: 07/27/2013] [Indexed: 12/20/2022]
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