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Rivera-Chávez F, Winter SE, Lopez CA, Xavier MN, Winter MG, Nuccio SP, Russell JM, Laughlin RC, Lawhon SD, Sterzenbach T, Bevins CL, Tsolis RM, Harshey R, Adams LG, Bäumler AJ. Salmonella uses energy taxis to benefit from intestinal inflammation. PLoS Pathog 2013; 9:e1003267. [PMID: 23637594 PMCID: PMC3630101 DOI: 10.1371/journal.ppat.1003267] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 02/08/2013] [Indexed: 01/18/2023] Open
Abstract
Chemotaxis enhances the fitness of Salmonella enterica serotype Typhimurium (S. Typhimurium) during colitis. However, the chemotaxis receptors conferring this fitness advantage and their cognate signals generated during inflammation remain unknown. Here we identify respiratory electron acceptors that are generated in the intestinal lumen as by-products of the host inflammatory response as in vivo signals for methyl-accepting chemotaxis proteins (MCPs). Three MCPs, including Trg, Tsr and Aer, enhanced the fitness of S. Typhimurium in a mouse colitis model. Aer mediated chemotaxis towards electron acceptors (energy taxis) in vitro and required tetrathionate respiration to confer a fitness advantage in vivo. Tsr mediated energy taxis towards nitrate but not towards tetrathionate in vitro and required nitrate respiration to confer a fitness advantage in vivo. These data suggest that the energy taxis receptors Tsr and Aer respond to distinct in vivo signals to confer a fitness advantage upon S. Typhimurium during inflammation by enabling this facultative anaerobic pathogen to seek out favorable spatial niches containing host-derived electron acceptors that boost its luminal growth.
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Affiliation(s)
- Fabian Rivera-Chávez
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, Davis, California, United States of America
| | - Sebastian E. Winter
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, Davis, California, United States of America
| | - Christopher A. Lopez
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, Davis, California, United States of America
| | - Mariana N. Xavier
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, Davis, California, United States of America
| | - Maria G. Winter
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, Davis, California, United States of America
| | - Sean-Paul Nuccio
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, Davis, California, United States of America
| | - Joseph M. Russell
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, Davis, California, United States of America
| | - Richard C. Laughlin
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Sara D. Lawhon
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Torsten Sterzenbach
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, Davis, California, United States of America
| | - Charles L. Bevins
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, Davis, California, United States of America
| | - Renée M. Tsolis
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, Davis, California, United States of America
| | - Rasika Harshey
- Section of Molecular Genetics and Microbiology, School of Biological Sciences, University of Texas at Austin, Austin, Texas, United States of America
| | - L. Garry Adams
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Andreas J. Bäumler
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, Davis, California, United States of America
- * E-mail:
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102
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Nanton MR, Way SS, Shlomchik MJ, McSorley SJ. Cutting edge: B cells are essential for protective immunity against Salmonella independent of antibody secretion. THE JOURNAL OF IMMUNOLOGY 2012; 189:5503-7. [PMID: 23150714 DOI: 10.4049/jimmunol.1201413] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Typhoid fever and nontyphoidal bacteremia caused by Salmonella remain critical human health problems. B cells are required for protective immunity to Salmonella, but the mechanism of protection remains unclear. In this study, we immunized wild-type, B cell-deficient, Ab-deficient, and class-switched Ab-deficient mice with attenuated Salmonella and examined protection against secondary infection. As expected, wild-type mice were protected and B cell-deficient mice succumbed to secondary infection. Interestingly, mice with B cells but lacking secreted Ab or class-switched Ab had little deficiency in resistance to Salmonella infection. The susceptibility of B cell-deficient mice correlated with marked reductions in CD4 T cell IFN-γ production after secondary infection. Taken together, these data suggest that the primary role of B cells in acquired immunity to Salmonella is via the development of protective T cell immunity.
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Affiliation(s)
- Minelva R Nanton
- Department of Pediatric Infectious Disease, Center for Infectious Diseases and Microbiology Translational Research, University of Minnesota Medical School-Twin Cities, Minneapolis, MN 55455, USA.
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103
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Genome expression analysis of nonproliferating intracellular Salmonella enterica serovar Typhimurium unravels an acid pH-dependent PhoP-PhoQ response essential for dormancy. Infect Immun 2012; 81:154-65. [PMID: 23090959 DOI: 10.1128/iai.01080-12] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Genome-wide expression analyses have provided clues on how Salmonella proliferates inside cultured macrophages and epithelial cells. However, in vivo studies show that Salmonella does not replicate massively within host cells, leaving the underlying mechanisms of such growth control largely undefined. In vitro infection models based on fibroblasts or dendritic cells reveal limited proliferation of the pathogen, but it is presently unknown whether these phenomena reflect events occurring in vivo. Fibroblasts are distinctive, since they represent a nonphagocytic cell type in which S. enterica serovar Typhimurium actively attenuates intracellular growth. Here, we show in the mouse model that S. Typhimurium restrains intracellular growth within nonphagocytic cells positioned in the intestinal lamina propria. This response requires a functional PhoP-PhoQ system and is reproduced in primary fibroblasts isolated from the mouse intestine. The fibroblast infection model was exploited to generate transcriptome data, which revealed that ∼2% (98 genes) of the S. Typhimurium genome is differentially expressed in nongrowing intracellular bacteria. Changes include metabolic reprogramming to microaerophilic conditions, induction of virulence plasmid genes, upregulation of the pathogenicity islands SPI-1 and SPI-2, and shutdown of flagella production and chemotaxis. Comparison of relative protein levels of several PhoP-PhoQ-regulated functions (PagN, PagP, and VirK) in nongrowing intracellular bacteria and extracellular bacteria exposed to diverse PhoP-PhoQ-inducing signals denoted a regulation responding to acidic pH. These data demonstrate that S. Typhimurium restrains intracellular growth in vivo and support a model in which dormant intracellular bacteria could sense vacuolar acidification to stimulate the PhoP-PhoQ system for preventing intracellular overgrowth.
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104
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Barat S, Willer Y, Rizos K, Claudi B, Mazé A, Schemmer AK, Kirchhoff D, Schmidt A, Burton N, Bumann D. Immunity to intracellular Salmonella depends on surface-associated antigens. PLoS Pathog 2012; 8:e1002966. [PMID: 23093937 PMCID: PMC3475680 DOI: 10.1371/journal.ppat.1002966] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 08/14/2012] [Indexed: 01/05/2023] Open
Abstract
Invasive Salmonella infection is an important health problem that is worsening because of rising antimicrobial resistance and changing Salmonella serovar spectrum. Novel vaccines with broad serovar coverage are needed, but suitable protective antigens remain largely unknown. Here, we tested 37 broadly conserved Salmonella antigens in a mouse typhoid fever model, and identified antigen candidates that conferred partial protection against lethal disease. Antigen properties such as high in vivo abundance or immunodominance in convalescent individuals were not required for protectivity, but all promising antigen candidates were associated with the Salmonella surface. Surprisingly, this was not due to superior immunogenicity of surface antigens compared to internal antigens as had been suggested by previous studies and novel findings for CD4 T cell responses to model antigens. Confocal microscopy of infected tissues revealed that many live Salmonella resided alone in infected host macrophages with no damaged Salmonella releasing internal antigens in their vicinity. In the absence of accessible internal antigens, detection of these infected cells might require CD4 T cell recognition of Salmonella surface-associated antigens that could be processed and presented even from intact Salmonella. In conclusion, our findings might pave the way for development of an efficacious Salmonella vaccine with broad serovar coverage, and suggest a similar crucial role of surface antigens for immunity to both extracellular and intracellular pathogens. Salmonella infections cause extensive morbidity and mortality worldwide. A vaccine that prevents systemic Salmonella infections is urgently needed but suitable antigens remain largely unknown. In this study we identified several antigen candidates that mediated protective immunity to Salmonella in a mouse typhoid fever model. Interestingly, all these antigens were associated with the Salmonella surface. This suggested that similar antigen properties might be relevant for CD4 T cell dependent immunity to intracellular pathogens like Salmonella, as for antibody-dependent immunity to extracellular pathogens. Detailed analysis revealed that Salmonella surface antigens were not generally more immunogenic compared to internal antigens. However, internal antigens were inaccessible for CD4 T cell recognition of a substantial number of infected host cells that contained exclusively live intact Salmonella. Together, these results might pave the way for development of an efficacious Salmonella vaccine, and provide a basis to facilitate antigen identification for Salmonella and possibly other intracellular pathogens.
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Affiliation(s)
- Somedutta Barat
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Yvonne Willer
- Junior Group “Mucosal Infections”, Hannover Medical School, Hannover, Germany
| | - Konstantin Rizos
- Department of Molecular Biology, Max-Planck-Institute for Infection Biology, Berlin, Germany
| | - Beatrice Claudi
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Alain Mazé
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Anne K. Schemmer
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Dennis Kirchhoff
- Immunomodulation Group, Deutsches Rheuma-Forschungszentrum Berlin, Berlin, Germany
| | - Alexander Schmidt
- Proteomics Core Facility, Biozentrum, University of Basel, Basel, Switzerland
| | - Neil Burton
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Dirk Bumann
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
- Junior Group “Mucosal Infections”, Hannover Medical School, Hannover, Germany
- Department of Molecular Biology, Max-Planck-Institute for Infection Biology, Berlin, Germany
- * E-mail:
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105
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Kröger C, Dillon SC, Cameron ADS, Papenfort K, Sivasankaran SK, Hokamp K, Chao Y, Sittka A, Hébrard M, Händler K, Colgan A, Leekitcharoenphon P, Langridge GC, Lohan AJ, Loftus B, Lucchini S, Ussery DW, Dorman CJ, Thomson NR, Vogel J, Hinton JCD. The transcriptional landscape and small RNAs of Salmonella enterica serovar Typhimurium. Proc Natl Acad Sci U S A 2012; 109:E1277-86. [PMID: 22538806 PMCID: PMC3356629 DOI: 10.1073/pnas.1201061109] [Citation(s) in RCA: 301] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
More than 50 y of research have provided great insight into the physiology, metabolism, and molecular biology of Salmonella enterica serovar Typhimurium (S. Typhimurium), but important gaps in our knowledge remain. It is clear that a precise choreography of gene expression is required for Salmonella infection, but basic genetic information such as the global locations of transcription start sites (TSSs) has been lacking. We combined three RNA-sequencing techniques and two sequencing platforms to generate a robust picture of transcription in S. Typhimurium. Differential RNA sequencing identified 1,873 TSSs on the chromosome of S. Typhimurium SL1344 and 13% of these TSSs initiated antisense transcripts. Unique findings include the TSSs of the virulence regulators phoP, slyA, and invF. Chromatin immunoprecipitation revealed that RNA polymerase was bound to 70% of the TSSs, and two-thirds of these TSSs were associated with σ(70) (including phoP, slyA, and invF) from which we identified the -10 and -35 motifs of σ(70)-dependent S. Typhimurium gene promoters. Overall, we corrected the location of important genes and discovered 18 times more promoters than identified previously. S. Typhimurium expresses 140 small regulatory RNAs (sRNAs) at early stationary phase, including 60 newly identified sRNAs. Almost half of the experimentally verified sRNAs were found to be unique to the Salmonella genus, and <20% were found throughout the Enterobacteriaceae. This description of the transcriptional map of SL1344 advances our understanding of S. Typhimurium, arguably the most important bacterial infection model.
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Affiliation(s)
- Carsten Kröger
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, and
| | - Shane C. Dillon
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, and
| | - Andrew D. S. Cameron
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, and
| | - Kai Papenfort
- Institute for Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany
| | - Sathesh K. Sivasankaran
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, and
| | - Karsten Hokamp
- Department of Genetics, School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Yanjie Chao
- Institute for Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany
| | - Alexandra Sittka
- Molecular Pulmonology, Universities of Giessen and Marburg Lung Center, German Center for Lung Research, Philipps University, 35043 Marburg, Germany
| | - Magali Hébrard
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, and
| | - Kristian Händler
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, and
| | - Aoife Colgan
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, and
| | - Pimlapas Leekitcharoenphon
- Department of Systems Biology, Center for Biological Sequence Analysis, and
- National Food Institute, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Gemma C. Langridge
- The Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, United Kingdom
| | - Amanda J. Lohan
- School of Medicine and Medical Science, Conway Institute, University College Dublin, Dublin 4, Ireland; and
| | - Brendan Loftus
- School of Medicine and Medical Science, Conway Institute, University College Dublin, Dublin 4, Ireland; and
| | - Sacha Lucchini
- Institute of Food Research, Colney, Norwich NR4 7UA, United Kingdom
| | - David W. Ussery
- Department of Systems Biology, Center for Biological Sequence Analysis, and
| | - Charles J. Dorman
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, and
| | - Nicholas R. Thomson
- The Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, United Kingdom
| | - Jörg Vogel
- Institute for Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany
| | - Jay C. D. Hinton
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, and
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106
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Pilonieta MC, Nagy TA, Jorgensen DR, Detweiler CS. A glycine betaine importer limits Salmonella stress resistance and tissue colonization by reducing trehalose production. Mol Microbiol 2012; 84:296-309. [PMID: 22375627 DOI: 10.1111/j.1365-2958.2012.08022.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Mechanisms by which Salmonella establish chronic infections are not well understood. Microbes respond to stress by importing or producing compatible solutes, small molecules that stabilize proteins and lipids. The Salmonella locus opuABCD (also called OpuC) encodes a predicted importer of the compatible solute glycine betaine. Under stress conditions, if glycine betaine cannot be imported, Salmonella enterica produce the disaccharide trehalose, a highly effective compatible solute. We demonstrate that strains lacking opuABCD accumulate more trehalose under stress conditions than wild-type strains. ΔopuABCD mutant strains are more resistant to high-salt, low-pH and -hydrogen peroxide, conditions that mimic aspects of innate immunity, in a trehalose-dependent manner. In addition, ΔopuABCD mutant strains require the trehalose production genes to out-compete wild-type strains in mice and macrophages. These data suggest that in the absence of opuABCD, trehalose accumulation increases bacterial resistance to stress in broth and mice. Thus, opuABCD reduces bacterial colonization via a mechanism that limits trehalose production. Mechanisms by which microbes limit disease may reveal novel pathways as therapeutic targets.
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Affiliation(s)
- M Carolina Pilonieta
- Department of Molecular Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA.
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107
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Thiennimitr P, Winter SE, Bäumler AJ. Salmonella, the host and its microbiota. Curr Opin Microbiol 2011; 15:108-14. [PMID: 22030447 DOI: 10.1016/j.mib.2011.10.002] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 09/30/2011] [Accepted: 10/04/2011] [Indexed: 11/30/2022]
Abstract
The intestine is host to a diverse bacterial community whose structure, at the phylum level, is maintained through unknown mechanisms. Acute inflammation triggered by enteric pathogens, such as Salmonella enterica serotype Typhimurium (S. Typhimurium), is accompanied by changes in the bacterial community structure marked by an outgrowth of the pathogen. Recent studies show that S. Typhimurium can harness benefit from the host response to edge out the beneficial bacterial species that dominate in the healthy gut. The elucidation of how S. Typhimurium alters the bacterial community structure during gastroenteritis is beginning to provide insights into mechanisms that dictate the balance between the host and its microbiota.
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Affiliation(s)
- Parameth Thiennimitr
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, United States
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108
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Abstract
Non-typhoidal Salmonella (NTS) serotypes cause a localized gastroenteritis in immunocompetent individuals. In contrast, primary immunodeficiencies that impair interleukin-23 (IL-23)-dependent pathways are associated in humans with disseminated NTS bloodstream infections (bacteraemia). The recent use of animal models has helped to define the role the IL-23 axis plays during NTS gastroenteritis, but additional work is needed to elucidate how this host defence pathway prevents NTS bacteraemia.
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Affiliation(s)
- Ivan Godinez
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA, USA
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109
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Ahmer BMM, Gunn JS. Interaction of Salmonella spp. with the Intestinal Microbiota. Front Microbiol 2011; 2:101. [PMID: 21772831 PMCID: PMC3131049 DOI: 10.3389/fmicb.2011.00101] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Accepted: 04/25/2011] [Indexed: 12/20/2022] Open
Abstract
Salmonella spp. are major cause of human morbidity and mortality worldwide. Upon entry into the human host, Salmonella spp. must overcome the resistance to colonization mediated by the gut microbiota and the innate immune system. They successfully accomplish this by inducing inflammation and mechanisms of innate immune defense. Many models have been developed to study Salmonella spp. interaction with the microbiota that have helped to identify factors necessary to overcome colonization resistance and to mediate disease. Here we review the current state of studies into this important pathogen/microbiota/host interaction in the mammalian gastrointestinal tract.
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Affiliation(s)
- Brian M M Ahmer
- The Department of Microbiology, The Ohio State University Columbus, OH, USA
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