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Zhang L, Zheng B, Lu J, Wu H, Wu H, Zhang Q, Jiao L, Pan H, Zhou J. Evaluation of human antibodies from vaccinated volunteers for protection against Yersinia pestis infection. Microbiol Spectr 2024:e0105424. [PMID: 39189763 DOI: 10.1128/spectrum.01054-24] [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: 04/26/2024] [Accepted: 07/26/2024] [Indexed: 08/28/2024] Open
Abstract
Yersinia pestis has a broad host range and has caused lethal bubonic and pneumonic plague in humans. With the emergence of multiple resistant strains and the potential for biothreat use, there is an urgent need for new therapeutic strategies that can protect populations from natural or deliberate infection. Targeting F1 has been proven to be the main strategy for developing vaccines and therapeutic antibodies, but data on anti-F1 antibodies, especially in humans, are scarce. To date, three human anti-F1 monoclonal antibodies (m252, αF1Ig2, and αF1Ig8) from naive populations have been reported. Here, we constructed an antibody library from vaccinees immunized with the plague subunit vaccine IIa by phage display. The genetic basis, epitopes, and biological functions of the obtained mAbs were assessed and evaluated in plague-challenged mice. Three human mAbs, namely, F3, F19, and F23, were identified. Their biolayer responses were 0.4, 0.6, and 0.6 nm, respectively. The dissociation constants (KD) of the F1 antigen were 1 pM, 0.165 nM, and 1 pM, respectively. Although derived from distinct Ab lineages, that is, VH3-30-D3-10-JH4 (F3&F23) and VH3-43-D6-19-JH4 (F19), these mAbs share similar binding sites in F1 with some overlap with αF1Ig8 but are distinct from αF1Ig2. Each of them provided a significant protective effect for Balb/c mice against a 100 median lethal dose (MLD) challenge of a virulent Y. pestis strain when administered at a dose of 100 µg. No synergistic or antagonistic effects were observed among them. These mAbs are novel and excellent candidates for further drug development and use in clinical practice.IMPORTANCEIn this study, we identified three human monoclonal antibodies with a high affinity to F1 protein of Yersinia pestis. We discovered that they have relatively lower somatic hypermutations compared with antibodies, m252, αF1Ig2, and αF1Ig8, derived from the naive library reported previously. We also observed that these mAbs share similar binding sites in F1 with some overlapping with αF1Ig8 but distinct from that of αF1Ig2. Furthermore, each of them could provide complete protection for mice against a lethal dose of Yersinia pestis challenge. Our data provided new insights into the anti-F1 Ab repertories and their associated epitopes during vaccination in humans. The findings support the additional novel protective human anti-F1Abs for potential therapeutics against plaque.
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Affiliation(s)
- Li Zhang
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases (NITFID), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Binyang Zheng
- Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Jing Lu
- Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Haisheng Wu
- Qinghai Institute for Endemic Disease Control and Prevention, Xining, China
| | - Hailian Wu
- Qinghai Institute for Endemic Disease Control and Prevention, Xining, China
| | - Qi Zhang
- Qinghai Institute for Endemic Disease Control and Prevention, Xining, China
| | - Lei Jiao
- Lanzhou Institute of Biological Products Co., Ltd., State Key Laboratory of Novel Vaccines for Emerging Infectious Diseases, Lanzhou, China
| | - Hongxing Pan
- Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Jianfang Zhou
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases (NITFID), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
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2
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Moreno S, Muriel-Millán LF, Rodríguez-Martínez K, Ortíz-Vasco C, Bedoya-Pérez LP, Espín G. The ribosome rescue pathways SsrA-SmpB, ArfA, and ArfB mediate tolerance to heat and antibiotic stresses in Azotobacter vinelandii. FEMS Microbiol Lett 2022; 369:6824435. [PMID: 36368695 DOI: 10.1093/femsle/fnac104] [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: 02/18/2022] [Revised: 08/29/2022] [Accepted: 10/31/2022] [Indexed: 11/13/2022] Open
Abstract
Bacteria have a mechanism to rescue stalled ribosomes known as trans-translation consisting of SsrA, a transfer-messenger RNA (tmRNA), and the small protein SmpB. Other alternative rescue mechanisms mediated by ArfA and ArfB proteins are present only in some species. Ribosome rescue mechanisms also play a role in tolerance to antibiotics and various stresses such as heat. This study shows that the genome of the soil bacterium A. vinelandii harbours genes encoding for tmRNA, SmpB, two paralogs of ArfA (arfA1 and arfA2), and ArfB. A number of mutant strains carrying mutations in the ssrA, arfA1, arfA2, and arfB genes were constructed and tested for their growth and susceptibility to heat and the antibiotic tetracycline. We found that the inactivation of both ssrA and one or the two arfA genes was detrimental to growth and caused a higher susceptibility to heat and to the antibiotic tetracycline. Interestingly, the arfB mutant strain was unable to grow after 2 h of incubation at 45°C. Inactivation of arfB in the ssrA-arfA1-arfA2 strain caused a lethal phenotype since the quadruple mutant could not be isolated. Taken together, our data suggest that both arfA1 and arfA2, as well as arfB, are functional as back up mechanisms, and that the ArfB pathway has an essential role that confers A. vinelandii resistance to high temperatures.
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Affiliation(s)
- Soledad Moreno
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos 62210, México
| | - Luis Felipe Muriel-Millán
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510 Ciudad Universitaria, CDMX, México
| | - Karen Rodríguez-Martínez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos 62210, México
| | - Cristian Ortíz-Vasco
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos 62210, México
| | - Leidy Patricia Bedoya-Pérez
- Programa de Biología Sintética, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos 62210, México
| | - Guadalupe Espín
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos 62210, México
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3
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Baseggio L, Silayeva O, Buller N, Landos M, Englestädter J, Barnes AC. Complete, closed and curated genome sequences of Photobacterium damselae subsp. piscicida isolates from Australia indicate mobilome-driven localized evolution and novel pathogenicity determinants. Microb Genom 2021; 7:000562. [PMID: 33885359 PMCID: PMC8208687 DOI: 10.1099/mgen.0.000562] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Despite the recent advances in sequencing technologies, the complete assembly of multi-chromosome genomes of the Vibrionaceae, often containing several plasmids, remains challenging. Using a combination of Oxford Nanopore MinION long reads and short Illumina reads, we fully sequenced, closed and curated the genomes of two strains of a primary aquatic pathogen Photobacterium damselae subsp. piscicida isolated in Australia. These are also the first genome sequences of P. damselae subsp. piscicida isolated in Oceania and, to our knowledge, in the Southern hemisphere. We also investigated the phylogenetic relationships between Australian and overseas isolates, revealing that Australian P. damselae subsp. piscicida are more closely related to the Asian and American strains rather than to the European ones. We investigated the mobilome and present new evidence showing that a host specialization process and progressive adaptive evolution to fish are ongoing in P. damselae subsp. piscicida, and are largely mediated by transposable elements, predominantly in chromosome 2, and by plasmids. Finally, we identified two novel potential virulence determinants in P. damselae subsp. piscicida - a chorismate mutase gene, which is ubiquitously retained and co-localized with the AIP56 apoptogenic toxin-encoding gene on the pPHDP10 plasmid, and transfer-messenger RNA gene ssrA located on the main chromosome, homologous to a critical-to-virulence determinant in Yersinia pseudotuberculosis. Our study describes, to our knowledge, the only fully closed and manually curated genomes of P. damselae subsp. piscicida available to date, offering new insights into this important fish pathogen and its evolution.
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Affiliation(s)
- Laura Baseggio
- School of Biological Sciences, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Oleksandra Silayeva
- School of Biological Sciences, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Nicky Buller
- Diagnostic and Laboratory Services (DDLS), Department of Primary Industries and Regional Development (DPIRD), 3 Baron-Hay Court, South Perth, Western Australia 6151, Australia
| | - Matt Landos
- Future Fisheries Veterinary Services, East Ballina, New South Wales 2478, Australia
| | - Jan Englestädter
- School of Biological Sciences, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Andrew C. Barnes
- School of Biological Sciences, University of Queensland, Brisbane, Queensland 4072, Australia
- *Correspondence: Andrew C. Barnes,
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4
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Susat J, Bonczarowska JH, Pētersone-Gordina E, Immel A, Nebel A, Gerhards G, Krause-Kyora B. Yersinia pestis strains from Latvia show depletion of the pla virulence gene at the end of the second plague pandemic. Sci Rep 2020; 10:14628. [PMID: 32884081 PMCID: PMC7471286 DOI: 10.1038/s41598-020-71530-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 08/04/2020] [Indexed: 11/28/2022] Open
Abstract
Ancient genomic studies have identified Yersinia pestis (Y. pestis) as the causative agent of the second plague pandemic (fourteenth–eighteenth century) that started with the Black Death (1,347–1,353). Most of the Y. pestis strains investigated from this pandemic have been isolated from western Europe, and not much is known about the diversity and microevolution of this bacterium in eastern European countries. In this study, we investigated human remains excavated from two cemeteries in Riga (Latvia). Historical evidence suggests that the burials were a consequence of plague outbreaks during the seventeenth century. DNA was extracted from teeth of 16 individuals and subjected to shotgun sequencing. Analysis of the metagenomic data revealed the presence of Y. pestis sequences in four remains, confirming that the buried individuals were victims of plague. In two samples, Y. pestis DNA coverage was sufficient for genome reconstruction. Subsequent phylogenetic analysis showed that the Riga strains fell within the diversity of the already known post-Black Death genomes. Interestingly, the two Latvian isolates did not cluster together. Moreover, we detected a drop in coverage of the pPCP1 plasmid region containing the pla gene. Further analysis indicated the presence of two pPCP1 plasmids, one with and one without the pla gene region, and only one bacterial chromosome, indicating that the same bacterium carried two distinct pPCP1 plasmids. In addition, we found the same pattern in the majority of previously published post-Black Death strains, but not in the Black Death strains. The pla gene is an important virulence factor for the infection of and transmission in humans. Thus, the spread of pla-depleted strains may, among other causes, have contributed to the disappearance of the second plague pandemic in eighteenth century Europe.
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Affiliation(s)
- Julian Susat
- Institute of Clinical Molecular Biology, Kiel University, Rosalind-Franklin-Straße 12, 24105, Kiel, Germany
| | - Joanna H Bonczarowska
- Institute of Clinical Molecular Biology, Kiel University, Rosalind-Franklin-Straße 12, 24105, Kiel, Germany
| | | | - Alexander Immel
- Institute of Clinical Molecular Biology, Kiel University, Rosalind-Franklin-Straße 12, 24105, Kiel, Germany
| | - Almut Nebel
- Institute of Clinical Molecular Biology, Kiel University, Rosalind-Franklin-Straße 12, 24105, Kiel, Germany
| | - Guntis Gerhards
- Institute of Latvian History, University of Latvia, Kalpaka bulvāris 4, Riga, 1050, Latvia
| | - Ben Krause-Kyora
- Institute of Clinical Molecular Biology, Kiel University, Rosalind-Franklin-Straße 12, 24105, Kiel, Germany.
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5
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Tresse C, Radigue R, Gomes Von Borowski R, Thepaut M, Hanh Le H, Demay F, Georgeault S, Dhalluin A, Trautwetter A, Ermel G, Blanco C, van de Weghe P, Jean M, Giard JC, Gillet R. Synthesis and evaluation of 1,3,4-oxadiazole derivatives for development as broad-spectrum antibiotics. Bioorg Med Chem 2019; 27:115097. [DOI: 10.1016/j.bmc.2019.115097] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 09/06/2019] [Accepted: 09/09/2019] [Indexed: 10/26/2022]
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6
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Yersinia enterocolitica. Food Microbiol 2019. [DOI: 10.1128/9781555819972.ch16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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7
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Sun W, Singh AK. Plague vaccine: recent progress and prospects. NPJ Vaccines 2019; 4:11. [PMID: 30792905 PMCID: PMC6379378 DOI: 10.1038/s41541-019-0105-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 12/19/2018] [Indexed: 01/14/2023] Open
Abstract
Three great plague pandemics, resulting in nearly 200 million deaths in human history and usage as a biowarfare agent, have made Yersinia pestis as one of the most virulent human pathogens. In late 2017, a large plague outbreak raged in Madagascar attracted extensive attention and caused regional panics. The evolution of local outbreaks into a pandemic is a concern of the Centers for Disease Control and Prevention (CDC) in plague endemic regions. Until now, no licensed plague vaccine is available. Prophylactic vaccination counteracting this disease is certainly a primary choice for its long-term prevention. In this review, we summarize the latest advances in research and development of plague vaccines.
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Affiliation(s)
- Wei Sun
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, NY 12208 USA
| | - Amit K. Singh
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, NY 12208 USA
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8
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Chatterjee R, Shreenivas MM, Sunil R, Chakravortty D. Enteropathogens: Tuning Their Gene Expression for Hassle-Free Survival. Front Microbiol 2019; 9:3303. [PMID: 30687282 PMCID: PMC6338047 DOI: 10.3389/fmicb.2018.03303] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 12/19/2018] [Indexed: 12/27/2022] Open
Abstract
Enteropathogenic bacteria have been the cause of the majority of foodborne illnesses. Much of the research has been focused on elucidating the mechanisms by which these pathogens evade the host immune system. One of the ways in which they achieve the successful establishment of a niche in the gut microenvironment and survive is by a chain of elegantly regulated gene expression patterns. Studies have shown that this process is very elaborate and is also regulated by several factors. Pathogens like, enteropathogenic Escherichia coli (EPEC), Salmonella Typhimurium, Shigellaflexneri, Yersinia sp. have been seen to employ various regulated gene expression strategies. These include toxin-antitoxin systems, quorum sensing systems, expression controlled by nucleoid-associated proteins (NAPs), several regulons and operons specific to these pathogens. In the following review, we have tried to discuss the common gene regulatory systems of enteropathogenic bacteria as well as pathogen-specific regulatory mechanisms.
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Affiliation(s)
- Ritika Chatterjee
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India.,Division of Biological Sciences, Indian Institute of Science, Bengaluru, India
| | - Meghanashree M Shreenivas
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India.,Division of Biological Sciences, Indian Institute of Science, Bengaluru, India.,Undergraduate Studies, Indian Institute of Science, Bengaluru, India
| | - Rohith Sunil
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India.,Division of Biological Sciences, Indian Institute of Science, Bengaluru, India.,Undergraduate Studies, Indian Institute of Science, Bengaluru, India
| | - Dipshikha Chakravortty
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India.,Division of Biological Sciences, Indian Institute of Science, Bengaluru, India.,Centre for Biosystems Science and Engineering, Indian Institute of Science, Bengaluru, India
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9
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Knittel V, Vollmer I, Volk M, Dersch P. Discovering RNA-Based Regulatory Systems for Yersinia Virulence. Front Cell Infect Microbiol 2018; 8:378. [PMID: 30460205 PMCID: PMC6232918 DOI: 10.3389/fcimb.2018.00378] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/05/2018] [Indexed: 12/26/2022] Open
Abstract
The genus Yersinia includes three human pathogenic species, Yersinia pestis, the causative agent of the bubonic and pneumonic plague, and enteric pathogens Y. enterocolitica and Y. pseudotuberculosis that cause a number of gut-associated diseases. Over the past years a large repertoire of RNA-based regulatory systems has been discovered in these pathogens using different RNA-seq based approaches. Among them are several conserved or species-specific RNA-binding proteins, regulatory and sensory RNAs as well as various RNA-degrading enzymes. Many of them were shown to control the expression of important virulence-relevant factors and have a very strong impact on Yersinia virulence. The precise targets, the molecular mechanism and their role for Yersinia pathogenicity is only known for a small subset of identified genus- or species-specific RNA-based control elements. However, the ongoing development of new RNA-seq based methods and data analysis methods to investigate the synthesis, composition, translation, decay, and modification of RNAs in the bacterial cell will help us to generate a more comprehensive view of Yersinia RNA biology in the near future.
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Affiliation(s)
- Vanessa Knittel
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ines Vollmer
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Marcel Volk
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
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10
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Macé K, Demay F, Guyomar C, Georgeault S, Giudice E, Goude R, Trautwetter A, Ermel G, Blanco C, Gillet R. A Genetic Tool to Quantify trans-Translation Activity in Vivo. J Mol Biol 2017; 429:3617-3625. [PMID: 29031699 DOI: 10.1016/j.jmb.2017.10.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 09/29/2017] [Accepted: 10/08/2017] [Indexed: 11/17/2022]
Abstract
In bacteria, trans-translation is the main quality control mechanism for rescuing ribosomes arrested during translation. This key process is universally conserved and plays a critical role in the viability and virulence of many pathogens. We developed a reliable in vivo double-fluorescence reporter system for the simultaneous quantification of both trans-translation and the associated proteolysis activities in bacteria. The assay was validated using mutant bacteria lacking tmRNA, SmpB, and the ClpP protease. Both antisense tmRNA-binding RNA and a peptide mimicking the SmpB C-terminal tail proved to be potent inhibitors of trans-translation in vivo. The double-fluorescent reporter was also tested with KKL-35, an oxadiazole derivative that is supposed to be a promising trans-translation inhibitor, and it surprisingly turns out that trans-translation is not the only target of KKL-35 in vivo.
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Affiliation(s)
- Kevin Macé
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France
| | - Fanny Demay
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France
| | - Charlotte Guyomar
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France
| | - Sylvie Georgeault
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France
| | - Emmanuel Giudice
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France
| | - Renan Goude
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France
| | - Annie Trautwetter
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France
| | - Gwennola Ermel
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France
| | - Carlos Blanco
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France.
| | - Reynald Gillet
- Univ. Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, 35000 Rennes, France.
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11
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Liu P, Huang D, Hu X, Tang Y, Ma X, Yan R, Han Q, Guo J, Zhang Y, Sun Q, Liu Z. Targeting Inhibition of SmpB by Peptide Aptamer Attenuates the Virulence to Protect Zebrafish against Aeromonas veronii Infection. Front Microbiol 2017; 8:1766. [PMID: 28955325 PMCID: PMC5601406 DOI: 10.3389/fmicb.2017.01766] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Accepted: 08/31/2017] [Indexed: 11/21/2022] Open
Abstract
Aeromonas veronii is an important pathogen of aquatic animals, wherein Small protein B (SmpB) is required for pathogenesis by functioning as both a component in stalled-ribosome rescue and a transcription factor in upregulation of virulence gene bvgS expression. Here a specific peptide aptamer PA-1 was selected from peptide aptamer library by bacterial two-hybrid system employing pBT-SmpB as bait. The binding affinity between SmpB and PA-1 was evaluated using enzyme-linked immunosorbent assay. The key amino acids of SmpB that interact with PA-1 were identified. After PA-1 was introduced into A. veronii, the engineered strain designated as A. veronii (pN-PA-1) was more sensitive and grew slower under salt stress in comparison with wild type, as the disruption of SmpB by PA-1 resulted in significant transcription reductions of virulence-related genes. Consistent with these observations, A. veronii (pN-PA-1) was severely attenuated in model organism zebrafish, and vaccination of zebrafish with A. veronii (pN-PA-1) induced a strong antibody response. The vaccinated zebrafish were well protected against subsequent lethal challenges with virulent parental strain. Collectively, we propose that targeting inhibition of SmpB by peptide aptamer PA-1 possesses the desired qualities for a live attenuated vaccine against pathogenic A. veronii.
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Affiliation(s)
- Peng Liu
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Biological Sciences, Hainan UniversityHaikou, China
| | - Dongyi Huang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Biological Sciences, Hainan UniversityHaikou, China
| | - Xinwen Hu
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Biological Sciences, Hainan UniversityHaikou, China
| | - Yanqiong Tang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Biological Sciences, Hainan UniversityHaikou, China
| | - Xiang Ma
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Biological Sciences, Hainan UniversityHaikou, China
| | - Rihui Yan
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Biological Sciences, Hainan UniversityHaikou, China
| | - Qian Han
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Biological Sciences, Hainan UniversityHaikou, China
| | - Jianchun Guo
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural SciencesHaikou, China
| | - Yueling Zhang
- Department of Biology, College of Science, Shantou UniversityShantou, China
| | - Qun Sun
- Department of Biotechnology, College of Life Sciences, Sichuan UniversityChengdu, China
| | - Zhu Liu
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Biological Sciences, Hainan UniversityHaikou, China
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12
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Senior NJ, Sasidharan K, Saint RJ, Scott AE, Sarkar-Tyson M, Ireland PM, Bullifent HL, Rong Yang Z, Moore K, Oyston PCF, Atkins TP, Atkins HS, Soyer OS, Titball RW. An integrated computational-experimental approach reveals Yersinia pestis genes essential across a narrow or a broad range of environmental conditions. BMC Microbiol 2017; 17:163. [PMID: 28732479 PMCID: PMC5521123 DOI: 10.1186/s12866-017-1073-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/17/2017] [Indexed: 01/07/2023] Open
Abstract
Background The World Health Organization has categorized plague as a re-emerging disease and the potential for Yersinia pestis to also be used as a bioweapon makes the identification of new drug targets against this pathogen a priority. Environmental temperature is a key signal which regulates virulence of the bacterium. The bacterium normally grows outside the human host at 28 °C. Therefore, understanding the mechanisms that the bacterium used to adapt to a mammalian host at 37 °C is central to the development of vaccines or drugs for the prevention or treatment of human disease. Results Using a library of over 1 million Y. pestis CO92 random mutants and transposon-directed insertion site sequencing, we identified 530 essential genes when the bacteria were cultured at 28 °C. When the library of mutants was subsequently cultured at 37 °C we identified 19 genes that were essential at 37 °C but not at 28 °C, including genes which encode proteins that play a role in enabling functioning of the type III secretion and in DNA replication and maintenance. Using genome-scale metabolic network reconstruction we showed that growth conditions profoundly influence the physiology of the bacterium, and by combining computational and experimental approaches we were able to identify 54 genes that are essential under a broad range of conditions. Conclusions Using an integrated computational-experimental approach we identify genes which are required for growth at 37 °C and under a broad range of environments may be the best targets for the development of new interventions to prevent or treat plague in humans. Electronic supplementary material The online version of this article (doi:10.1186/s12866-017-1073-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nicola J Senior
- College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4SB, UK
| | - Kalesh Sasidharan
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Richard J Saint
- Defence Science Technology Laboratory, Porton Down, Salisbury, SP4 OJQ, UK
| | - Andrew E Scott
- Defence Science Technology Laboratory, Porton Down, Salisbury, SP4 OJQ, UK
| | - Mitali Sarkar-Tyson
- Defence Science Technology Laboratory, Porton Down, Salisbury, SP4 OJQ, UK.,Marshall Centre for Infectious Disease Research and Training, School of Pathology and Laboratory Medicine, University of Western Australia, Perth, WA, 6009, Australia
| | - Philip M Ireland
- Defence Science Technology Laboratory, Porton Down, Salisbury, SP4 OJQ, UK
| | - Helen L Bullifent
- Defence Science Technology Laboratory, Porton Down, Salisbury, SP4 OJQ, UK
| | - Z Rong Yang
- College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4SB, UK
| | - Karen Moore
- College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4SB, UK
| | - Petra C F Oyston
- Defence Science Technology Laboratory, Porton Down, Salisbury, SP4 OJQ, UK
| | - Timothy P Atkins
- College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4SB, UK.,Defence Science Technology Laboratory, Porton Down, Salisbury, SP4 OJQ, UK
| | - Helen S Atkins
- College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4SB, UK.,Defence Science Technology Laboratory, Porton Down, Salisbury, SP4 OJQ, UK
| | - Orkun S Soyer
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Richard W Titball
- College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4SB, UK.
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13
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Nuss AM, Heroven AK, Dersch P. RNA Regulators: Formidable Modulators of Yersinia Virulence. Trends Microbiol 2016; 25:19-34. [PMID: 27651123 DOI: 10.1016/j.tim.2016.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 08/08/2016] [Accepted: 08/24/2016] [Indexed: 10/21/2022]
Abstract
A large repertoire of RNA-based regulatory mechanisms, including a plethora of cis- and trans-acting noncoding RNAs (ncRNAs), sensory RNA elements, regulatory RNA-binding proteins, and RNA-degrading enzymes have been uncovered lately as key players in the regulation of metabolism, stress responses, and virulence of the genus Yersinia. Many of them are strictly controlled in response to fluctuating environmental conditions sensed during the course of the infection, and certain riboregulators have already been shown to be crucial for virulence. Some of them are highly conserved among the family Enterobacteriaceae, while others are genus-, species-, or strain-specific and could contribute to the difference in Yersinia pathogenicity. Importantly, the analysis of Yersinia riboregulators has not only uncovered crucial elements and regulatory mechanisms governing host-pathogen interactions, it also revealed exciting new venues for the design of novel anti-infectives.
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Affiliation(s)
- Aaron M Nuss
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ann Kathrin Heroven
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany.
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14
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Abstract
Y. pestis exhibits dramatically different traits of pathogenicity and transmission, albeit their close genetic relationship with its ancestor-Y. pseudotuberculosis, a self-limiting gastroenteric pathogen. Y. pestis is evolved into a deadly pathogen and transmitted to mammals and/or human beings by infected flea biting or directly contacting with the infected animals. Various kinds of environmental changes are implicated into its complex life cycle and pathogenesis. Dynamic regulation of gene expression is critical for environmental adaptation or survival, primarily reflected by genetic regulation mediated by transcriptional factors and small regulatory RNAs at the transcriptional and posttranscriptional level, respectively. The effects of genetic regulation have been shown to profoundly influence Y. pestis physiology and pathogenesis such as stress resistance, biofilm formation, intracellular survival, and replication. In this chapter, we mainly summarize the progresses on popular methods of genetic regulation and on regulatory patterns and consequences of many key transcriptional and posttranscriptional regulators, with a particular emphasis on how genetic regulation influences the biofilm and virulence of Y. pestis.
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15
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Abstract
Three major plague pandemics caused by the gram-negative bacterium Yersinia pestis have killed nearly 200 million people in human history. Due to its extreme virulence and the ease of its transmission, Y. pestis has been used purposefully for biowarfare in the past. Currently, plague epidemics are still breaking out sporadically in most of parts of the world, including the United States. Approximately 2000 cases of plague are reported each year to the World Health Organization. However, the potential use of the bacteria in modern times as an agent of bioterrorism and the emergence of a Y. pestis strain resistant to eight antibiotics bring out severe public health concerns. Therefore, prophylactic vaccination against this disease holds the brightest prospect for its long-term prevention. Here, we summarize the progress of the current vaccine development for counteracting plague.
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Affiliation(s)
- Wei Sun
- Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, 110880, Gainesville, FL, 32611-0880, USA.
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16
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Sun W, Sanapala S, Rahav H, Curtiss R. Oral administration of a recombinant attenuated Yersinia pseudotuberculosis strain elicits protective immunity against plague. Vaccine 2015; 33:6727-35. [PMID: 26514425 DOI: 10.1016/j.vaccine.2015.10.074] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 09/16/2015] [Accepted: 10/14/2015] [Indexed: 01/14/2023]
Abstract
A Yersinia pseudotuberculosis PB1+ (Yptb PB1+) mutant strain combined with chromosome insertion of the caf1R-caf1A-caf1M-caf1 operon and deletions of yopJ and yopK, χ10068 [pYV-ω2 (ΔyopJ315 ΔyopK108) ΔlacZ044::caf1R-caf1M-caf1A-caf1] was constructed. Results indicated that gene insertion and deletion did not affect the growth rate of χ10068 compared to wild-type Yptb cultured at 26 °C. In addition, the F1 antigen in χ10068 was synthesized and secreted on the surface of bacteria at 37 °C (mammalian body temperature), not at ambient culture temperature (26 °C). Immunization with χ10068 primed antibody responses and specific T-cell responses to F1 and YpL (Y. pestis whole cell lysate). Oral immunization with a single dose of χ10068 provided 70% protection against a subcutaneous (s.c.) challenge with ∼ 2.6 × 10(5) LD50 of Y. pestis KIM6+ (pCD1Ap) (KIM6+Ap) and 90% protection against an intranasal (i.n.) challenge with ∼ 500 LD50 of KIM6+Ap in mice. Our results suggest that χ10068 can be used as an effective precursor to make a safe vaccine to prevent plague in humans and to eliminate plague circulation among humans and animals.
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Affiliation(s)
- Wei Sun
- Center for Infectious Disease and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA.
| | - Shilpa Sanapala
- Center for Infectious Disease and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA
| | - Hannah Rahav
- Center for Infectious Disease and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA
| | - Roy Curtiss
- Center for Infectious Disease and Vaccinology, The Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA; School of Life Sciences, Arizona State University, Tempe, AZ, USA
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17
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Martínez-Chavarría LC, Vadyvaloo V. Yersinia pestis and Yersinia pseudotuberculosis infection: a regulatory RNA perspective. Front Microbiol 2015; 6:956. [PMID: 26441890 PMCID: PMC4585118 DOI: 10.3389/fmicb.2015.00956] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 08/28/2015] [Indexed: 12/27/2022] Open
Abstract
Yersinia pestis, responsible for causing fulminant plague, has evolved clonally from the enteric pathogen, Y. pseudotuberculosis, which in contrast, causes a relatively benign enteric illness. An ~97% nucleotide identity over 75% of their shared protein coding genes is maintained between these two pathogens, leaving much conjecture regarding the molecular determinants responsible for producing these vastly different disease etiologies, host preferences and transmission routes. One idea is that coordinated production of distinct factors required for host adaptation and virulence in response to specific environmental cues could contribute to the distinct pathogenicity distinguishing these two species. Small non-coding RNAs that direct posttranscriptional regulation have recently been identified as key molecules that may provide such timeous expression of appropriate disease enabling factors. Here the burgeoning field of small non-coding regulatory RNAs in Yersinia pathogenesis is reviewed from the viewpoint of adaptive colonization, virulence and divergent evolution of these pathogens.
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Affiliation(s)
- Luary C Martínez-Chavarría
- Departamento de Patología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, México Mexico
| | - Viveka Vadyvaloo
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA USA
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18
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19
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Abstract
La synthèse des protéines, également appelée traduction, est assurée dans chaque cellule par des machines moléculaires très sophistiquées : les ribosomes. Compte tenu de l’immense quantité de données biologiques à traiter, il arrive régulièrement que ces machines se bloquent et mettent en péril la survie de la cellule. Chez les bactéries, le principal processus de sauvetage des ribosomes bloqués est la trans-traduction. Il est assuré par un acide ribonucléique (ARN) hybride, l’ARN transfert-messager (ARNtm), associé à une petite protéine basique, SmpB (small protein B). Plusieurs autres systèmes de contrôle qualité ont récemment été mis en évidence, révélant un réseau de maintien de la survie cellulaire très sophistiqué. Cette machinerie du contrôle qualité de la synthèse protéique est une cible très prometteuse pour le développement de futurs antibiotiques.
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20
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Wilton J, Acebo P, Herranz C, Gómez A, Amblar M. Small regulatory RNAs in Streptococcus pneumoniae: discovery and biological functions. Front Genet 2015; 6:126. [PMID: 25904932 PMCID: PMC4387999 DOI: 10.3389/fgene.2015.00126] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 03/17/2015] [Indexed: 12/23/2022] Open
Abstract
Streptococcus pneumoniae is a prominent human pathogen responsible for many severe diseases and the leading cause of childhood mortality worldwide. The pneumococcus is remarkably adept at colonizing and infecting different niches in the human body, and its adaptation to dynamic host environment is a central aspect of its pathogenesis. In the last decade, increasing findings have evidenced small RNAs (sRNAs) as vital regulators in a number of important processes in bacteria. In S. pneumoniae, a small antisense RNA was first discovered in the pMV158 plasmid as a copy number regulator. More recently, genome-wide screens revealed that the pneumococcal genome also encodes multiple sRNAs, many of which have important roles in virulence while some are implicated in competence control. The knowledge of the sRNA-mediated regulation in pneumococcus remains very limited, and future research is needed for better understanding of functions and mechanisms. Here, we provide a comprehensive summary of the current knowledge on sRNAs from S. pneumoniae, focusing mainly on the trans-encoded sRNAs.
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Affiliation(s)
- Joana Wilton
- Unidad de Patología Molecular del Neumococo, Centro Nacional de Microbiología, Instituto de Salud Carlos III Madrid, Spain
| | - Paloma Acebo
- Unidad de Patología Molecular del Neumococo, Centro Nacional de Microbiología, Instituto de Salud Carlos III Madrid, Spain
| | - Cristina Herranz
- Unidad de Patología Molecular del Neumococo, Centro Nacional de Microbiología, Instituto de Salud Carlos III Madrid, Spain
| | - Alicia Gómez
- Unidad de Patología Molecular del Neumococo, Centro Nacional de Microbiología, Instituto de Salud Carlos III Madrid, Spain
| | - Mónica Amblar
- Unidad de Patología Molecular del Neumococo, Centro Nacional de Microbiología, Instituto de Salud Carlos III Madrid, Spain ; CIBER Enfermedades Respiratorias Madrid, Spain
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21
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Rollat-Farnier PA, Santos-Garcia D, Rao Q, Sagot MF, Silva FJ, Henri H, Zchori-Fein E, Latorre A, Moya A, Barbe V, Liu SS, Wang XW, Vavre F, Mouton L. Two host clades, two bacterial arsenals: evolution through gene losses in facultative endosymbionts. Genome Biol Evol 2015; 7:839-55. [PMID: 25714744 PMCID: PMC5322557 DOI: 10.1093/gbe/evv030] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Bacterial endosymbiosis is an important evolutionary process in insects, which can harbor both obligate and facultative symbionts. The evolution of these symbionts is driven by evolutionary convergence, and they exhibit among the tiniest genomes in prokaryotes. The large host spectrum of facultative symbionts and the high diversity of strategies they use to infect new hosts probably impact the evolution of their genome and explain why they undergo less severe genomic erosion than obligate symbionts. Candidatus Hamiltonella defensa is suitable for the investigation of the genomic evolution of facultative symbionts because the bacteria are engaged in specific relationships in two clades of insects. In aphids, H. defensa is found in several species with an intermediate prevalence and confers protection against parasitoids. In whiteflies, H. defensa is almost fixed in some species of Bemisia tabaci, which suggests an important role of and a transition toward obligate symbiosis. In this study, comparisons of the genome of H. defensa present in two B. tabaci species (Middle East Asia Minor 1 and Mediterranean) and in the aphid Acyrthosiphon pisum revealed that they belong to two distinct clades and underwent specific gene losses. In aphids, it contains highly virulent factors that could allow protection and horizontal transfers. In whiteflies, the genome lost these factors and seems to have a limited ability to acquire genes. However it contains genes that could be involved in the production of essential nutrients, which is consistent with a primordial role for this symbiont. In conclusion, although both lineages of H. defensa have mutualistic interactions with their hosts, their genomes follow distinct evolutionary trajectories that reflect their phenotype and could have important consequences on their evolvability.
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Affiliation(s)
- Pierre-Antoine Rollat-Farnier
- Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université de Lyon, Université Lyon1, Villeurbanne, France BAMBOO Research Team, INRIA Grenoble, Rhône-Alpes, France
| | - Diego Santos-Garcia
- Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Spain
| | - Qiong Rao
- Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China School of Agriculture and Food Science, Zhejiang Agriculture and Forestry University, Lin'an, Hangzhou, China
| | - Marie-France Sagot
- Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université de Lyon, Université Lyon1, Villeurbanne, France BAMBOO Research Team, INRIA Grenoble, Rhône-Alpes, France
| | - Francisco J Silva
- Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Spain Unidad Mixta de Investigación en Genómica y Salud de la Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunidad Valenciana (FISABIO-Salud Pública) y el Instituto Cavanilles de Biodiversitad y Biología Evolutiva (Universitat de València), Valencia, Spain
| | - Hélène Henri
- Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université de Lyon, Université Lyon1, Villeurbanne, France
| | - Einat Zchori-Fein
- Department of Entomology, NeweYa'ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Amparo Latorre
- Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Spain Unidad Mixta de Investigación en Genómica y Salud de la Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunidad Valenciana (FISABIO-Salud Pública) y el Instituto Cavanilles de Biodiversitad y Biología Evolutiva (Universitat de València), Valencia, Spain
| | - Andrés Moya
- Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Spain Unidad Mixta de Investigación en Genómica y Salud de la Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunidad Valenciana (FISABIO-Salud Pública) y el Instituto Cavanilles de Biodiversitad y Biología Evolutiva (Universitat de València), Valencia, Spain
| | - Valérie Barbe
- CEA/DSV/IG/Genoscope, 2 rue Gaston Cremieux, Evry, France
| | - Shu-Sheng Liu
- Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Xiao-Wei Wang
- Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Fabrice Vavre
- Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université de Lyon, Université Lyon1, Villeurbanne, France BAMBOO Research Team, INRIA Grenoble, Rhône-Alpes, France
| | - Laurence Mouton
- Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université de Lyon, Université Lyon1, Villeurbanne, France
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22
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Venkataraman K, Zafar H, Karzai AW. Distinct tmRNA sequence elements facilitate RNase R engagement on rescued ribosomes for selective nonstop mRNA decay. Nucleic Acids Res 2014; 42:11192-202. [PMID: 25200086 PMCID: PMC4176180 DOI: 10.1093/nar/gku802] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
trans-Translation, orchestrated by SmpB and tmRNA, is the principal eubacterial pathway for resolving stalled translation complexes. RNase R, the leading nonstop mRNA surveillance factor, is recruited to stalled ribosomes in a trans-translation dependent process. To elucidate the contributions of SmpB and tmRNA to RNase R recruitment, we evaluated Escherichia coli–Francisella tularensis chimeric variants of tmRNA and SmpB. This evaluation showed that while the hybrid tmRNA supported nascent polypeptide tagging and ribosome rescue, it suffered defects in facilitating RNase R recruitment to stalled ribosomes. To gain further insights, we used established tmRNA and SmpB variants that impact distinct stages of the trans-translation process. Analysis of select tmRNA variants revealed that the sequence composition and positioning of the ultimate and penultimate codons of the tmRNA ORF play a crucial role in recruiting RNase R to rescued ribosomes. Evaluation of defined SmpB C-terminal tail variants highlighted the importance of establishing the tmRNA reading frame, and provided valuable clues into the timing of RNase R recruitment to rescued ribosomes. Taken together, these studies demonstrate that productive RNase R-ribosomes engagement requires active trans-translation, and suggest that RNase R captures the emerging nonstop mRNA at an early stage after establishment of the tmRNA ORF as the surrogate mRNA template.
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Affiliation(s)
- Krithika Venkataraman
- Department of Biochemistry and Cell Biology, Center for Infectious Diseases, Stony Brook University, Stony Brook, New York, NY 11794, USA
| | - Hina Zafar
- Department of Biochemistry and Cell Biology, Center for Infectious Diseases, Stony Brook University, Stony Brook, New York, NY 11794, USA
| | - A Wali Karzai
- Department of Biochemistry and Cell Biology, Center for Infectious Diseases, Stony Brook University, Stony Brook, New York, NY 11794, USA
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23
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LcrV delivered via type III secretion system of live attenuated Yersinia pseudotuberculosis enhances immunogenicity against pneumonic plague. Infect Immun 2014; 82:4390-404. [PMID: 25114109 DOI: 10.1128/iai.02173-14] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Here, we constructed a Yersinia pseudotuberculosis mutant strain with arabinose-dependent regulated and delayed shutoff of crp expression (araC P(BAD) crp) and replacement of the msbB gene with the Escherichia coli msbB gene to attenuate it. Then, we inserted the asd mutation into this construction to form χ10057 [Δasd-206 ΔmsbB868::P(msbB) msbB(EC) ΔP(crp21)::TT araC P(BAD) crp] for use with a balanced-lethal Asd-positive (Asd(+)) plasmid to facilitate antigen synthesis. A hybrid protein composed of YopE (amino acids [aa]1 to 138) fused with full-length LcrV (YopE(Nt138)-LcrV) was synthesized in χ10057 harboring an Asd(+) plasmid (pYA5199, yopE(Nt138)-lcrV) and could be secreted through a type III secretion system (T3SS) in vitro and in vivo. Animal studies indicated that mice orally immunized with χ10057(pYA5199) developed titers of IgG response to whole-cell lysates of Y. pestis (YpL) and subunit LcrV similar to those seen with χ10057(pYA3332) (χ10057 plus an empty plasmid). However, only immunization of mice with χ10057(pYA5199) resulted in a significant secretory IgA response to LcrV. χ10057(pYA5199) induced a higher level of protection (80% survival) against intranasal (i.n.) challenge with ~240 median lethal doses (LD50) (2.4 × 10(4) CFU) of Y. pestis KIM6+(pCD1Ap) than χ10057(pYA3332) (40% survival). Splenocytes from mice vaccinated with χ10057(pYA5199) produced significant levels of gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), and interleukin-17 (IL-17) after restimulation with LcrV and YpL antigens. Our results suggest that it is possible to use an attenuated Y. pseudotuberculosis strain delivering the LcrV antigen via the T3SS as a potential vaccine candidate against pneumonic plague.
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Abstract
Problems during gene expression can result in a ribosome that has translated to the 3' end of an mRNA without terminating at a stop codon, forming a nonstop translation complex. The nonstop translation complex contains a ribosome with the mRNA and peptidyl-tRNA engaged, but because there is no codon in the A site, the ribosome cannot elongate or terminate the nascent chain. Recent work has illuminated the importance of resolving these nonstop complexes in bacteria. Transfer-messenger RNA (tmRNA)-SmpB specifically recognizes and resolves nonstop translation complexes in a reaction known as trans-translation. trans-Translation releases the ribosome and promotes degradation of the incomplete nascent polypeptide and problematic mRNA. tmRNA and SmpB have been found in all bacteria and are essential in some species. However, other bacteria can live without trans-translation because they have one of the alternative release factors, ArfA or ArfB. ArfA recruits RF2 to nonstop translation complexes to promote hydrolysis of the peptidyl-tRNAs. ArfB recognizes nonstop translation complexes in a manner similar to tmRNA-SmpB recognition and directly hydrolyzes the peptidyl-tRNAs to release the stalled ribosomes. Genetic studies indicate that most or all species require at least one mechanism to resolve nonstop translation complexes. Consistent with such a requirement, small molecules that inhibit resolution of nonstop translation complexes have broad-spectrum antibacterial activity. These results suggest that resolving nonstop translation complexes is a matter of life or death for bacteria.
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25
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Wang X, Zhang X, Zhou D, Yang R. Live-attenuatedYersinia pestisvaccines. Expert Rev Vaccines 2014; 12:677-86. [DOI: 10.1586/erv.13.42] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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26
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Zhang Q, Wang Q, Tian G, Qi Z, Zhang X, Wu X, Qiu Y, Bi Y, Yang X, Xin Y, He J, Zhou J, Zeng L, Yang R, Wang X. Yersinia pestis biovar Microtus strain 201, an avirulent strain to humans, provides protection against bubonic plague in rhesus macaques. Hum Vaccin Immunother 2013; 10:368-77. [PMID: 24225642 DOI: 10.4161/hv.27060] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Yersinia pestis biovar Microtus is considered to be a virulent to larger mammals, including guinea pigs, rabbits and humans. It may be used as live attenuated plague vaccine candidates in terms of its low virulence. However, the Microtus strain's protection against plague has yet to be demonstrated in larger mammals. In this study, we evaluated the protective efficacy of the Microtus strain 201 as a live attenuated plague vaccine candidate. Our results show that this strain is highly attenuated by subcutaneous route, elicits an F1-specific antibody titer similar to the EV and provides a protective efficacy similar to the EV against bubonic plague in Chinese-origin rhesus macaques. The Microtus strain 201 could induce elevated secretion of both Th1-associated cytokines (IFN-γ, IL-2 and TNF-α) and Th2-associated cytokines (IL-4, IL-5, and IL-6), as well as chemokines MCP-1 and IL-8. However, the protected animals developed skin ulcer at challenge site with different severity in most of the immunized and some of the EV-immunized monkeys. Generally, the Microtus strain 201 represented a good plague vaccine candidate based on its ability to generate strong humoral and cell-mediated immune responses as well as its good protection against high dose of subcutaneous virulent Y. pestis challenge.
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Affiliation(s)
- Qingwen Zhang
- Anhui Medical University; Hefei, Anhui PR China; Qinghai Institute for Endemic Disease Prevention and Control of Qinghai Province; Xining, PR China
| | - Qiong Wang
- Anhui Medical University; Hefei, Anhui PR China; Laboratory of Analytical Microbiology; State Key Laboratory of Pathogen and Biosecurity; Beijing Institute of Microbiology and Epidemiology; Beijing, PR China
| | - Guang Tian
- Laboratory of Analytical Microbiology; State Key Laboratory of Pathogen and Biosecurity; Beijing Institute of Microbiology and Epidemiology; Beijing, PR China
| | - Zhizhen Qi
- Qinghai Institute for Endemic Disease Prevention and Control of Qinghai Province; Xining, PR China
| | - Xuecan Zhang
- Laboratory of Analytical Microbiology; State Key Laboratory of Pathogen and Biosecurity; Beijing Institute of Microbiology and Epidemiology; Beijing, PR China
| | - Xiaohong Wu
- Laboratory of Analytical Microbiology; State Key Laboratory of Pathogen and Biosecurity; Beijing Institute of Microbiology and Epidemiology; Beijing, PR China
| | - Yefeng Qiu
- Laboratory Animal Research Center; Academy of Military Medical Science; Beijing; PR China
| | - Yujing Bi
- Laboratory of Analytical Microbiology; State Key Laboratory of Pathogen and Biosecurity; Beijing Institute of Microbiology and Epidemiology; Beijing, PR China
| | - Xiaoyan Yang
- Qinghai Institute for Endemic Disease Prevention and Control of Qinghai Province; Xining, PR China
| | - Youquan Xin
- Qinghai Institute for Endemic Disease Prevention and Control of Qinghai Province; Xining, PR China
| | - Jian He
- Qinghai Institute for Endemic Disease Prevention and Control of Qinghai Province; Xining, PR China
| | - Jiyuan Zhou
- Laboratory of Analytical Microbiology; State Key Laboratory of Pathogen and Biosecurity; Beijing Institute of Microbiology and Epidemiology; Beijing, PR China
| | - Lin Zeng
- Laboratory Animal Research Center; Academy of Military Medical Science; Beijing; PR China
| | - Ruifu Yang
- Laboratory of Analytical Microbiology; State Key Laboratory of Pathogen and Biosecurity; Beijing Institute of Microbiology and Epidemiology; Beijing, PR China
| | - Xiaoyi Wang
- Anhui Medical University; Hefei, Anhui PR China; Laboratory of Analytical Microbiology; State Key Laboratory of Pathogen and Biosecurity; Beijing Institute of Microbiology and Epidemiology; Beijing, PR China
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27
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Keiler KC, Alumasa JN. The potential of trans-translation inhibitors as antibiotics. Future Microbiol 2013; 8:1235-7. [DOI: 10.2217/fmb.13.110] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Kenneth C Keiler
- Department of Food Science, The Pennsylvania State University, University Park, PA 16802, USA
| | - John N Alumasa
- Department of Food Science, The Pennsylvania State University, University Park, PA 16802, USA
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Yan Y, Su S, Meng X, Ji X, Qu Y, Liu Z, Wang X, Cui Y, Deng Z, Zhou D, Jiang W, Yang R, Han Y. Determination of sRNA expressions by RNA-seq in Yersinia pestis grown in vitro and during infection. PLoS One 2013; 8:e74495. [PMID: 24040259 PMCID: PMC3770706 DOI: 10.1371/journal.pone.0074495] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2013] [Accepted: 08/02/2013] [Indexed: 12/21/2022] Open
Abstract
Background Small non-coding RNAs (sRNAs) facilitate host-microbe interactions. They have a central function in the post-transcriptional regulation during pathogenic lifestyles. Hfq, an RNA-binding protein that many sRNAs act in conjunction with, is required for Y. pestis pathogenesis. However, information on how Yersinia pestis modulates the expression of sRNAs during infection is largely unknown. Methodology and Principal Findings We used RNA-seq technology to identify the sRNA candidates expressed from Y. pestis grown invitro and in the infected lungs of mice. A total of 104 sRNAs were found, including 26 previously annotated sRNAs, by searching against the Rfam database with 78 novel sRNA candidates. Approximately 89% (93/104) of these sRNAs from Y. pestis are shared with its ancestor Y. pseudotuberculosis. Ninety-seven percent of these sRNAs (101/104) are shared among more than 80 sequenced genomes of 135 Y. pestis strains. These 78 novel sRNAs include 62 intergenic and 16 antisense sRNAs. Fourteen sRNAs were selected for verification by independent Northern blot analysis. Results showed that nine selected sRNA transcripts were Hfq-dependent. Interestingly, three novel sRNAs were identified as new members of the transcription factor CRP regulon. Semi-quantitative analysis revealed that Y. pestis from the infected lungs induced the expressions of six sRNAs including RyhB1, RyhB2, CyaR/RyeE, 6S RNA, RybB and sR039 and repressed the expressions of four sRNAs, including CsrB, CsrC, 4.5S RNA and sR027. Conclusions and Significance This study is the first attempt to subject RNA from Y. pestis-infected samples to direct high-throughput sequencing. Many novel sRNAs were identified and the expression patterns of relevant sRNAs in Y. pestis during invitro growth and invivo infection were revealed. The annotated sRNAs accounted for the most abundant sRNAs either expressed in bacteria grown invitro or differentially expressed in the infected lungs. These findings suggested these sRNAs may have important functions in Y. pestis physiology or pathogenesis.
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Affiliation(s)
- Yanfeng Yan
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Shanchun Su
- Microbiology Laboratory, Sichuan Agricultural University, Yaan, Sichuan province, China
| | - Xiangrong Meng
- Clinical Laboratory, Huzhong Hispital, Guangzhou, Guangdong province, China
| | - Xiaolan Ji
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Yi Qu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Zizhong Liu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Xiaoyi Wang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Yujun Cui
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Zhongliang Deng
- Department of Sanitary Inspection, School of Public Health, University of South China, Hengyang, Hunan province, China
| | - Dongsheng Zhou
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Wencan Jiang
- Microbiology Laboratory, Sichuan Agricultural University, Yaan, Sichuan province, China
| | - Ruifu Yang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
- * E-mail: (YH); (RY)
| | - Yanping Han
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
- * E-mail: (YH); (RY)
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The transfer-messenger RNA-small protein B system plays a role in avian pathogenic Escherichia coli pathogenicity. J Bacteriol 2013; 195:5064-71. [PMID: 24013628 DOI: 10.1128/jb.00628-13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Extraintestinal pathogenic Escherichia coli (ExPEC) is capable of colonizing outside of the intestinal tract and evolving into a systemic infection. Avian pathogenic E. coli (APEC) is a member of the ExPEC group and causes avian colibacillosis. Transfer-mRNA-small protein B (tmRNA-SmpB)-mediated trans-translation is a bacterial translational control system that directs the modification and degradation of proteins, the biosynthesis of which has stalled or has been interrupted, facilitating the rescue of ribosomes stalled at the 3' ends of defective mRNAs that lack a stop codon. We found that disruption of one, or both, of the smpB or ssrA genes significantly decreased the virulence of the APEC strain E058, as assessed by chicken infection assays. Furthermore, the mutants were obviously attenuated in colonization and persistence assays. The results of quantitative real-time reverse transcription-PCR analysis indicated that the transcription levels of the transcriptional regulation gene rfaH and the virulence genes kpsM, chuA, and iss were significantly decreased compared to those of the wild-type strain. Macrophage infection assays showed that the mutant strains reduced the replication and/or survival ability in the macrophage HD11 cell line compared to that of the parent strain, E058. However, no significant differences were observed in ingestion by macrophages and in chicken serum resistance between the mutant and the wild-type strains. These data indicate that the tmRNA-SmpB system is important in the pathogenesis of APEC O2 strain E058.
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Camenares D, Dulebohn DP, Svetlanov A, Karzai AW. Active and accurate trans-translation requires distinct determinants in the C-terminal tail of SmpB protein and the mRNA-like domain of transfer messenger RNA (tmRNA). J Biol Chem 2013; 288:30527-30542. [PMID: 23986442 DOI: 10.1074/jbc.m113.503896] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Unproductive ribosome stalling in eubacteria is resolved by the actions of SmpB protein and transfer messenger (tm) RNA. We examined the functional significance of conserved regions of SmpB and tmRNA to the trans-translation process. Our investigations reveal that the N-terminal 20 residues of SmpB, which are located near the ribosomal decoding center, are dispensable for all known SmpB activities. In contrast, a set of conserved residues that reside at the junction between the tmRNA-binding core and the C-terminal tail of SmpB play an important role in tmRNA accommodation. Our data suggest that the highly conserved glycine 132 acts as a flexible hinge that enables movement of the C-terminal tail, thus permitting proper positioning and establishment of the tmRNA open reading frame (ORF) as the surrogate template. To gain further insights into the function of the SmpB C-terminal tail, we examined the tagging activity of hybrid variants of tmRNA and the SmpB protein, in which the tmRNA ORF or the SmpB C-terminal tail was substituted with the equivalent but highly divergent sequences from Francisella tularensis. We observed that the hybrid tmRNA was active but resulted in less accurate selection of the resume codon. Cognate hybrid SmpB was necessary to restore activity. Furthermore, accurate tagging was observed when the identity of the resume codon was reverted from GGC to GCA. Taken together, these data suggest that the engagement of the tmRNA ORF and the selection of the correct translation resumption point are distinct activities that are influenced by independent tmRNA and SmpB determinants.
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Affiliation(s)
- Devin Camenares
- From the Department of Biochemistry and Cell Biology and; Center for Infectious Diseases, Stony Brook University, Stony Brook, New York 11794
| | | | - Anton Svetlanov
- From the Department of Biochemistry and Cell Biology and; Center for Infectious Diseases, Stony Brook University, Stony Brook, New York 11794
| | - A Wali Karzai
- From the Department of Biochemistry and Cell Biology and; Center for Infectious Diseases, Stony Brook University, Stony Brook, New York 11794.
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Li J, Ji L, Shi W, Xie J, Zhang Y. Trans-translation mediates tolerance to multiple antibiotics and stresses in Escherichia coli. J Antimicrob Chemother 2013; 68:2477-81. [PMID: 23812681 DOI: 10.1093/jac/dkt231] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Trans-translation mediated by SsrA (tmRNA) and its associated protein SmpB plays an important role in rescuing stalled ribosomes and detoxifying toxic protein products under stress conditions. However, the role of SsrA and SmpB in bacterial persister survival has not been studied. The recent finding that pyrazinamide as a unique persister drug inhibits trans-translation in Mycobacterium tuberculosis prompted us to examine the role of trans-translation in persister survival. METHODS Using Escherichia coli as a model, we constructed SsrA and SmpB mutants and assessed the susceptibility of the mutants to various antibiotics and stress conditions in MIC/MBC and persister assays. RESULTS We found that mutations in SsrA and SmpB caused a defect in persister survival as shown by their increased susceptibility to a variety of antibiotics, including gentamicin, streptomycin, amikacin, norfloxacin, trimethoprim and tetracycline, and also stresses, such as acid, weak acid salicylate, heat and peroxide. Additionally, the SsrA and SmpB mutants were 2-8-fold more susceptible than the parent strain to various antibiotics in MIC and MBC tests. The SmpB mutant was more susceptible to antibiotics and stresses than the SsrA mutant. A particularly interesting finding is the hypersusceptibility of the SmpB mutant and the SsrA mutant to trimethoprim. The defect of various SsrA and SmpB mutant phenotypes could be complemented by functional ssrA and smpB, respectively. CONCLUSIONS We conclude that SsrA and SmpB are important for persister survival and may serve as a good target for developing new antibiotics that kill persister bacteria for improved treatment of persistent bacterial infections.
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Affiliation(s)
- Jinghua Li
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
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32
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Small molecule inhibitors of trans-translation have broad-spectrum antibiotic activity. Proc Natl Acad Sci U S A 2013; 110:10282-7. [PMID: 23733947 DOI: 10.1073/pnas.1302816110] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The trans-translation pathway for protein tagging and ribosome release plays a critical role for viability and virulence in a wide range of pathogens but is not found in animals. To explore the use of trans-translation as a target for antibiotic development, a high-throughput screen and secondary screening assays were used to identify small molecule inhibitors of the pathway. Compounds that inhibited protein tagging and proteolysis of tagged proteins were recovered from the screen. One of the most active compounds, KKL-35, inhibited the trans-translation tagging reaction with an IC50 = 0.9 µM. KKL-35 and other compounds identified in the screen exhibited broad-spectrum antibiotic activity, validating trans-translation as a target for drug development. This unique target could play a key role in combating strains of pathogenic bacteria that are resistant to existing antibiotics.
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Mellado-Sanchez G, Ramirez K, Drachenberg CB, Diaz-McNair J, Rodriguez AL, Galen JE, Nataro JP, Pasetti MF. Characterization of systemic and pneumonic murine models of plague infection using a conditionally virulent strain. Comp Immunol Microbiol Infect Dis 2012. [PMID: 23195858 DOI: 10.1016/j.cimid.2012.10.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Yersinia pestis causes bubonic and pneumonic plague in humans. The pneumonic infection is the most severe and invariably fatal if untreated. Because of its high virulence, ease of delivery and precedent of use in warfare, Y. pestis is considered as a potential bioterror agent. No licensed plague vaccine is currently available in the US. Laboratory research with virulent strains requires appropriate biocontainment (i.e., Biosafety Level 3 (BSL-3) for procedures that generate aerosol/droplets) and secure facilities that comply with federal select agent regulations. To assist in the identification of promising vaccine candidates during the early phases of development, we characterized mouse models of systemic and pneumonic plague infection using the Y. pestis strain EV76, an attenuated human vaccine strain that can be rendered virulent in mice under in vivo iron supplementation. Mice inoculated intranasally or intravenously with Y. pestis EV76 in the presence of iron developed a systemic and pneumonic plague infection that resulted in disease and lethality. Bacteria replicated and severely compromised the spleen, liver and lungs. Susceptibility was age dependent, with younger mice being more vulnerable to pneumonic infection. We used these models of infection to assess the protective capacity of newly developed Salmonella-based plague vaccines. The protective outcome varied depending on the route and dose of infection. Protection was associated with the induction of specific immunological effectors in systemic/mucosal compartments. The models of infection described could serve as safe and practical tools for identifying promising vaccine candidates that warrant further potency evaluation using fully virulent strains in BSL-3 settings.
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Affiliation(s)
- Gabriela Mellado-Sanchez
- Department of Pediatrics, Center for Vaccine Development, University of Maryland School of Medicine, 685 West Baltimore St., Room 480, Baltimore, MD 21201, USA
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Schiano CA, Lathem WW. Post-transcriptional regulation of gene expression in Yersinia species. Front Cell Infect Microbiol 2012; 2:129. [PMID: 23162797 PMCID: PMC3493969 DOI: 10.3389/fcimb.2012.00129] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 10/03/2012] [Indexed: 11/13/2022] Open
Abstract
Proper regulation of gene expression is required by bacterial pathogens to respond to continually changing environmental conditions and the host response during the infectious process. While transcriptional regulation is perhaps the most well understood form of controlling gene expression, recent studies have demonstrated the importance of post-transcriptional mechanisms of gene regulation that allow for more refined management of the bacterial response to host conditions. Yersinia species of bacteria are known to use various forms of post-transcriptional regulation for control of many virulence-associated genes. These include regulation by cis- and trans-acting small non-coding RNAs, RNA-binding proteins, RNases, and thermoswitches. The effects of these and other regulatory mechanisms on Yersinia physiology can be profound and have been shown to influence type III secretion, motility, biofilm formation, host cell invasion, intracellular survival and replication, and more. In this review, we discuss these and other post-transcriptional mechanisms and their influence on virulence gene regulation, with a particular emphasis on how these processes influence the virulence of Yersinia in the host.
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Affiliation(s)
- Chelsea A Schiano
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine Chicago, IL, USA
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35
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Mann B, van Opijnen T, Wang J, Obert C, Wang YD, Carter R, McGoldrick DJ, Ridout G, Camilli A, Tuomanen EI, Rosch JW. Control of virulence by small RNAs in Streptococcus pneumoniae. PLoS Pathog 2012; 8:e1002788. [PMID: 22807675 PMCID: PMC3395615 DOI: 10.1371/journal.ppat.1002788] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 05/22/2012] [Indexed: 01/10/2023] Open
Abstract
Small noncoding RNAs (sRNAs) play important roles in gene regulation in both prokaryotes and eukaryotes. Thus far, no sRNA has been assigned a definitive role in virulence in the major human pathogen Streptococcus pneumoniae. Based on the potential coding capacity of intergenic regions, we hypothesized that the pneumococcus produces many sRNAs and that they would play an important role in pathogenesis. We describe the application of whole-genome transcriptional sequencing to systematically identify the sRNAs of Streptococcus pneumoniae. Using this approach, we have identified 89 putative sRNAs, 56 of which are newly identified. Furthermore, using targeted genetic approaches and Tn-seq transposon screening, we demonstrate that many of the identified sRNAs have important global and niche-specific roles in virulence. These data constitute the most comprehensive analysis of pneumococcal sRNAs and provide the first evidence of the extensive roles of sRNAs in pneumococcal pathogenesis.
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Affiliation(s)
- Beth Mann
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Tim van Opijnen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Jianmin Wang
- Hartwell Center for Bioinformatics and Biotechnology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Caroline Obert
- Hartwell Center for Bioinformatics and Biotechnology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Yong-Dong Wang
- Hartwell Center for Bioinformatics and Biotechnology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Robert Carter
- Hartwell Center for Bioinformatics and Biotechnology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Daniel J. McGoldrick
- Hartwell Center for Bioinformatics and Biotechnology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Granger Ridout
- Hartwell Center for Bioinformatics and Biotechnology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Andrew Camilli
- Howard Hughes Medical Institute and Tufts University School of Medicine, Department of Molecular Biology and Microbiology, Boston, Massachusetts, United States of America
| | - Elaine I. Tuomanen
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Jason W. Rosch
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
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36
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Qu Y, Bi L, Ji X, Deng Z, Zhang H, Yan Y, Wang M, Li A, Huang X, Yang R, Han Y. Identification by cDNA cloning of abundant sRNAs in a human-avirulent Yersinia pestis strain grown under five different growth conditions. Future Microbiol 2012; 7:535-47. [PMID: 22439729 DOI: 10.2217/fmb.12.13] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
AIMS sRNA regulation is supposedly involved in the stress response of a pathogen during infection. Yersinia pestis, the etiologic agent of plague, must encounter temperature and microenvironment changes, given its lifestyle. Here, we used the cDNA cloning approach to discover full-length sRNA candidates that are highly expressed in Y. pestis under five different growth conditions. MATERIALS & METHODS The cDNA cloning approach was improved by combining the traditional cDNA library construction with the prevalent rapid amplification of cDNA ends and RNA size selection techniques. RESULTS In total, 43 RNA species, including six previously annotated sRNAs, were identified. Of these, 25 sRNAs were encoded on the antisense strand of the annotated genes. Interestingly, two of these sRNAs were found on the complementary strand of noncoding RNAs. In addition, eight novel sRNAs encoded in the intergenic regions were also revealed. Ten sRNA candidates chosen for the northern blot analysis were successfully detected. Analysis of the expression patterns of 29 candidate sRNAs showed that 24 sRNAs are highly abundant in Y. pestis upon entry into the stationary growth phase. CONCLUSION Our preliminary attempt at screening the novel sRNA candidates will lay the foundation for understanding the roles of sRNAs in Y. pestis physiology and pathogenesis.
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Affiliation(s)
- Yi Qu
- State Key Laboratory of Pathogen & Biosecurity, Beijing Institute of Microbiology & Epidemiology, Beijing, China
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Svetlanov A, Puri N, Mena P, Koller A, Karzai AW. Francisella tularensis tmRNA system mutants are vulnerable to stress, avirulent in mice, and provide effective immune protection. Mol Microbiol 2012; 85:122-41. [PMID: 22571636 PMCID: PMC3395464 DOI: 10.1111/j.1365-2958.2012.08093.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Through targeted inactivation of the ssrA and smpB genes, we establish that the trans-translation process is necessary for normal growth, adaptation to cellular stress and virulence by the bacterial pathogen Francisella tularensis. The mutant bacteria grow slower, have reduced resistance to heat and cold shocks, and are more sensitive to oxidative stress and sublethal concentrations of antibiotics. Modifications of the tmRNA tag and use of higher-resolution mass spectrometry approaches enabled the identification of a large number of native tmRNA substrates. Of particular significance to understanding the mechanism of trans-translation, we report the discovery of an extended tmRNA tag and extensive ladder-like pattern of endogenous protein-tagging events in F. tularensis that are likely to be a universal feature of tmRNA activity in eubacteria. Furthermore, the structural integrity and the proteolytic function of the tmRNA tag are both crucial for normal growth and virulence of F. tularensis. Significantly, trans-translation mutants of F. tularensis are impaired in replication within macrophages and are avirulent in mouse models of tularemia. By exploiting these attenuated phenotypes, we find that the mutant strains provide effective immune protection in mice against lethal intradermal, intraperitoneal and intranasal challenges with the fully virulent parental strain.
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Affiliation(s)
- Anton Svetlanov
- Center for Infectious Diseases and Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York, 11794
| | - Neha Puri
- Center for Infectious Diseases and Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York, 11794
| | - Patricio Mena
- Center for Infectious Diseases and Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York, 11794
| | - Antonius Koller
- The Proteomic Center, Stony Brook University, Stony Brook, New York, 11794
| | - A. Wali Karzai
- Center for Infectious Diseases and Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York, 11794
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Bozue J, Cote CK, Webster W, Bassett A, Tobery S, Little S, Swietnicki W. A Yersinia pestis YscN ATPase mutant functions as a live attenuated vaccine against bubonic plague in mice. FEMS Microbiol Lett 2012; 332:113-21. [PMID: 22537022 DOI: 10.1111/j.1574-6968.2012.02583.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 04/19/2012] [Accepted: 04/22/2012] [Indexed: 11/30/2022] Open
Abstract
Yersinia pestis is the causative agent responsible for bubonic and pneumonic plague. The bacterium uses the pLcr plasmid-encoded type III secretion system to deliver virulence factors into host cells. Delivery requires ATP hydrolysis by the YscN ATPase encoded by the yscN gene also on pLcr. A yscN mutant was constructed in the fully virulent CO92 strain containing a nonpolar, in-frame internal deletion within the gene. We demonstrate that CO92 with a yscN mutation was not able to secrete the LcrV protein (V-Antigen) and attenuated in a subcutaneous model of plague demonstrating that the YscN ATPase was essential for virulence. However, if the yscN mutant was complemented with a functional yscN gene in trans, virulence was restored. To evaluate the mutant as a live vaccine, Swiss-Webster mice were vaccinated twice with the ΔyscN mutant at varying doses and were protected against bubonic plague in a dose-dependent manner. Antibodies to F1 capsule but not to LcrV were detected in sera from the vaccinated mice. These preliminary results suggest a proof-of-concept for an attenuated, genetically engineered, live vaccine effective against bubonic plague.
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Affiliation(s)
- Joel Bozue
- Division of Bacteriology, US Army Medical Research Institute of Infectious Diseases, Ft. Detrick, MD, USA
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Koo JT, Lathem WW. Global discovery of small noncoding RNAs in pathogenic Yersinia species. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 954:305-14. [PMID: 22782777 DOI: 10.1007/978-1-4614-3561-7_38] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Jovanka T Koo
- Department of Microbiology-Immunology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA
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Janssen BD, Hayes CS. The tmRNA ribosome-rescue system. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2012; 86:151-91. [PMID: 22243584 DOI: 10.1016/b978-0-12-386497-0.00005-0] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The bacterial tmRNA quality control system monitors protein synthesis and recycles stalled translation complexes in a process termed "ribosome rescue." During rescue, tmRNA acts first as a transfer RNA to bind stalled ribosomes, then as a messenger RNA to add the ssrA peptide tag to the C-terminus of the nascent polypeptide chain. The ssrA peptide targets tagged peptides for proteolysis, ensuring rapid degradation of potentially deleterious truncated polypeptides. Ribosome rescue also facilitates turnover of the damaged messages responsible for translational arrest. Thus, tmRNA increases the fidelity of gene expression by promoting the synthesis of full-length proteins. In addition to serving as a global quality control system, tmRNA also plays important roles in bacterial development, pathogenesis, and environmental stress responses. This review focuses on the mechanism of tmRNA-mediated ribosome rescue and the role of tmRNA in bacterial physiology.
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Affiliation(s)
- Brian D Janssen
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California, USA
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41
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Sun W, Roland KL, Curtiss R. Developing live vaccines against plague. J Infect Dev Ctries 2011; 5:614-27. [PMID: 21918302 PMCID: PMC3932668 DOI: 10.3855/jidc.2030] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Revised: 05/20/2011] [Accepted: 05/22/2011] [Indexed: 12/13/2022] Open
Abstract
Three great plague pandemics caused by the gram-negative bacterium Yersinia pestis have killed nearly 200 million people and it has been linked to biowarfare in the past. Plague is endemic in many parts of the world. In addition, the risk of plague as a bioweapon has prompted increased research to develop plague vaccines against this disease. Injectable subunit vaccines are being developed in the United States and United Kingdom. However, the live attenuated Y. pestis-EV NIIEG strain has been used as a vaccine for more than 70 years in the former Soviet Union and in some parts of Asia and provides a high degree of efficacy against plague. This vaccine has not gained general acceptance because of safety concerns. In recent years, modern molecular biological techniques have been applied to Y. pestis to construct strains with specific defined mutations designed to create safe, immunogenic vaccines with potential for use in humans and as bait vaccines to reduce the load of Y. pestis in the environment. In addition, a number of live, vectored vaccines have been reported using attenuated viral vectors or attenuated Salmonella strains to deliver plague antigens. Here we summarize the progress of live attenuated vaccines against plagu.
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Affiliation(s)
- Wei Sun
- Center for Infectious Disease and Vaccinology, The Biodesign Institute and School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 , USA
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42
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Galindo CL, Rosenzweig JA, Kirtley ML, Chopra AK. Pathogenesis of Y. enterocolitica and Y. pseudotuberculosis in Human Yersiniosis. J Pathog 2011; 2011:182051. [PMID: 22567322 PMCID: PMC3335670 DOI: 10.4061/2011/182051] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 06/27/2011] [Accepted: 07/01/2011] [Indexed: 12/15/2022] Open
Abstract
Yersiniosis is a food-borne illness that has become more prevalent in recent years due to human transmission via the fecal-oral route and prevalence in farm animals. Yersiniosis is primarily caused by Yersinia enterocolitica and less frequently by Yersinia pseudotuberculosis. Infection is usually characterized by a self-limiting acute infection beginning in the intestine and spreading to the mesenteric lymph nodes. However, more serious infections and chronic conditions can also occur, particularly in immunocompromised individuals. Y. enterocolitica and Y. pseudotuberculosis are both heterogeneous organisms that vary considerably in their degrees of pathogenicity, although some generalizations can be ascribed to pathogenic variants. Adhesion molecules and a type III secretion system are critical for the establishment and progression of infection. Additionally, host innate and adaptive immune responses are both required for yersiniae clearance. Despite the ubiquity of enteric Yersinia species and their association as important causes of food poisoning world-wide, few national enteric pathogen surveillance programs include the yersiniae as notifiable pathogens. Moreover, no standard exists whereby identification and reporting systems can be effectively compared and global trends developed. This review discusses yersinial virulence factors, mechanisms of infection, and host responses in addition to the current state of surveillance, detection, and prevention of yersiniosis.
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Affiliation(s)
- Cristi L Galindo
- Department of Microbiology & Immunology, Sealy Center for Vaccine Development, Institute of Human Infections & Immunity, and the Galveston National Laboratory, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-1070, USA
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Plague: Infections of Companion Animals and Opportunities for Intervention. Animals (Basel) 2011; 1:242-55. [PMID: 26486314 DOI: 10.3390/ani1020242] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Revised: 06/20/2011] [Accepted: 06/20/2011] [Indexed: 11/17/2022] Open
Abstract
Plague is a zoonotic disease, normally circulating in rodent populations, transmitted to humans most commonly through the bite of an infected flea vector. Secondary infection of the lungs results in generation of infectious aerosols, which pose a significant hazard to close contacts. In enzootic areas, plague infections have been reported in owners and veterinarians who come into contact with infected pets. Dogs are relatively resistant, but can import infected fleas into the home. Cats are acutely susceptible, and can present a direct hazard to health. Reducing roaming and hunting behaviours, combined with flea control measures go some way to reducing the risk to humans. Various vaccine formulations have been developed which may be suitable to protect companion animals from contracting plague, and thus preventing onward transmission to man. Since transmission has resulted in a number of fatal cases of plague, the vaccination of domestic animals such as cats would seem a low cost strategy for reducing the risk of infection by this serious disease in enzootic regions.
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Plague: Infections of Companion Animals and Opportunities for Intervention. Animals (Basel) 2011. [PMID: 26486314 PMCID: PMC4513460 DOI: 10.3390/anil020242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Plague is a zoonotic disease, normally circulating in rodent populations, transmitted to humans most commonly through the bite of an infected flea vector. Secondary infection of the lungs results in generation of infectious aerosols, which pose a significant hazard to close contacts. In enzootic areas, plague infections have been reported in owners and veterinarians who come into contact with infected pets. Dogs are relatively resistant, but can import infected fleas into the home. Cats are acutely susceptible, and can present a direct hazard to health. Reducing roaming and hunting behaviours, combined with flea control measures go some way to reducing the risk to humans. Various vaccine formulations have been developed which may be suitable to protect companion animals from contracting plague, and thus preventing onward transmission to man. Since transmission has resulted in a number of fatal cases of plague, the vaccination of domestic animals such as cats would seem a low cost strategy for reducing the risk of infection by this serious disease in enzootic regions.
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Rosenzweig JA, Jejelowo O, Sha J, Erova TE, Brackman SM, Kirtley ML, van Lier CJ, Chopra AK. Progress on plague vaccine development. Appl Microbiol Biotechnol 2011; 91:265-86. [PMID: 21670978 DOI: 10.1007/s00253-011-3380-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 05/11/2011] [Accepted: 05/11/2011] [Indexed: 12/15/2022]
Abstract
Yersinia pestis (YP), the gram-negative plague bacterium, has shaped human history unlike any other pathogen known to mankind. YP (transmitted by the bite of an infected flea) diverged only recently from the related enteric pathogen Yersinia pseudotuberculosis but causes radically different diseases. Three forms of plague exist in humans: bubonic (swollen lymph nodes or bubos), septicemic (spread of YP through the lymphatics or bloodstream from the bubos to other organs), and contagious, pneumonic plague which can be communicated via YP-charged respiratory droplets resulting in person-person transmission and rapid death if left untreated (50-90% mortality). Despite the potential threat of weaponized YP being employed in bioterrorism and YP infections remaining prevalent in endemic regions of the world where rodent populations are high (including the four corner regions of the USA), an efficacious vaccine that confers immunoprotection has yet to be developed. This review article will describe the current vaccine candidates being evaluated in various model systems and provide an overall summary on the progress of this important endeavor.
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Affiliation(s)
- Jason A Rosenzweig
- Department of Biology, Center for Bionanotechnology and Environmental Research (CBER), Texas Southern University, 3100 Cleburne Street, Houston, TX 77004, USA.
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Keiler KC, Ramadoss NS. Bifunctional transfer-messenger RNA. Biochimie 2011; 93:1993-7. [PMID: 21664408 DOI: 10.1016/j.biochi.2011.05.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Accepted: 05/25/2011] [Indexed: 01/14/2023]
Abstract
Transfer-messenger RNA (tmRNA) is a bifunctional RNA that has properties of a tRNA and an mRNA. tmRNA uses these two functions to release ribosomes stalled during translation and target the nascent polypeptides for degradation. This concerted reaction, known as trans-translation, contributes to translational quality control and regulation of gene expression in bacteria. tmRNA is conserved throughout bacteria, and is one of the most abundant RNAs in the cell, suggesting that trans-translation is of fundamental importance for bacterial fitness. Mutants lacking tmRNA activity typically have severe phenotypes, including defects in viability, virulence, and responses to environmental stresses.
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Affiliation(s)
- Kenneth C Keiler
- Pennsylvania State University, Department of Biochemistry & Molecular Biology, 401 Althouse Lab, University Park, PA 16802, USA.
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Identification and characterization of small-molecule inhibitors of Yop translocation in Yersinia pseudotuberculosis. Antimicrob Agents Chemother 2010; 54:3241-54. [PMID: 20498321 DOI: 10.1128/aac.00364-10] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Type three secretion systems (TTSSs) are virulence factors found in many pathogenic Gram-negative species, including the family of pathogenic Yersinia spp. Yersinia pseudotuberculosis requires the translocation of a group of effector molecules, called Yops, to subvert the innate immune response and establish infection. Polarized transfer of Yops from bacteria to immune cells depends on several factors, including the presence of a functional TTSS, the successful attachment of Yersinia to the target cell, and translocon insertion into the target cell membrane. Here we employed a high-throughput screen to identify small molecules that block translocation of Yops into mammalian cells. We identified 6 compounds that inhibited translocation of effectors without affecting synthesis of TTSS components and secreted effectors, assembly of the TTSS, or secretion of effectors. One compound, C20, reduced adherence of Y. pseudotuberculosis to target cells. Additionally, the compounds caused leakage of Yops into the supernatant during infection and thus reduced polarized translocation. Furthermore, several molecules, namely, C20, C22, C24, C34, and C38, also inhibited ExoS-mediated cell rounding, suggesting that the compounds target factors that are conserved between Pseudomonas aeruginosa and Y. pseudotuberculosis. In summary, we have identified 6 compounds that specifically inhibit translocation of Yops into mammalian cells but not Yop synthesis or secretion.
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Biosafety level 2 model of pneumonic plague and protection studies with F1 and Psa. Infect Immun 2010; 78:3443-53. [PMID: 20498260 DOI: 10.1128/iai.00382-10] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Attenuated Yersinia pestis pgm strains, such as KIM5, lack the siderophore yersiniabactin. Strain KIM5 does not induce significant pneumonia when delivered intranasally. In this study, mice were found to develop pneumonia after intranasal challenge with strain KIM5 when they were injected intraperitoneally with iron dextran, though not with iron sulfate. KIM5-infected mice treated daily with 4 mg iron dextran died in 3 days with severe pneumonia. Pneumonia was less severe if 4 mg iron dextran was administered only once before infection. The best-studied experimental vaccine against plague currently consists of the Yersinia pestis capsular antigen F1 and the type 3 secreted protein LcrV. The F1 antigen was shown to be protective against KIM5 infections in mice administered iron dextran doses leading to light or severe pneumonia, supporting the use of an iron dextran-treated model of pneumonic plague. Since F1 has been reported to be incompletely protective in some primates, and bacterial isolates lacking F1 are still virulent, there has been considerable interest in identifying additional protective subunit immunogens. Here we showed that the highly conserved Psa fimbriae of Y. pestis (also called pH 6 antigen) are expressed in murine organs after infection through the respiratory tract. Studies with iron dextran-treated mice showed that vaccination with the Psa fimbrial protein together with an adjuvant afforded incomplete but significant protection in the mouse model described. Therefore, further investigations to fully characterize the protective properties of the Psa fimbriae are warranted.
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Duffield M, Cooper I, McAlister E, Bayliss M, Ford D, Oyston P. Predicting conserved essential genes in bacteria: in silico identification of putative drug targets. MOLECULAR BIOSYSTEMS 2010; 6:2482-9. [DOI: 10.1039/c0mb00001a] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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