<i>mig-14</i>Is a Horizontally Acquired, Host-Induced Gene Required for<i>Salmonella enterica</i>Lethal Infection in the Murine Model of Typhoid Fever

Valdivia, Raphael H.; Cirillo, Daniela María; Lee, Anthea K.; Bouley, Donna M.; Falkow, Stanley

doi:10.1128/iai.68.12.7126-7131.2000

Cited by 32 publications

(37 citation statements)

References 38 publications

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“…For instance, it was confirmed by mutational analysis that the DFI-isolated Salmonella enterica serovar Typhimurium mig14 gene (279) is required for lethal infection of mice (277). Recently, it was shown that mig14 encodes an inner membrane-associated protein that promotes persistent infection, survival within macrophages, and resistance to an antimicrobial peptide (23).…”

Section: Fun Genesmentioning

confidence: 84%

Unraveling the Secret Lives of Bacteria: Use of In Vivo Expression Technology and Differential Fluorescence Induction Promoter Traps as Tools for Exploring Niche-Specific Gene Expression

Rediers

Rainey

Vanderleyden

et al. 2005

Microbiol Mol Biol Rev

141

120

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A major challenge for microbiologists is to elucidate the strategies deployed by microorganisms to adapt to and thrive in highly complex and dynamic environments. In vitro studies, including those monitoring genomewide changes, have proven their value, but they can, at best, mimic only a subset of the ensemble of abiotic and biotic stimuli that microorganisms experience in their natural habitats. The widely used gene-to-phenotype approach involves the identification of altered niche-related phenotypes on the basis of gene inactivation. However, many traits contributing to ecological performance that, upon inactivation, result in only subtle or difficult to score phenotypic changes are likely to be overlooked by this otherwise powerful approach. Based on the premise that many, if not most, of the corresponding genes will be induced or upregulated in the environment under study, ecologically significant genes can alternatively be traced using the promoter trap techniques differential fluorescence induction and in vivo expression technology (IVET). The potential and limitations are discussed for the different IVET selection strategies and system-specific variants thereof. Based on a compendium of genes that have emerged from these promoter-trapping studies, several functional groups have been distinguished, and their physiological relevance is illustrated with follow-up studies of selected genes. In addition to confirming results from largely complementary approaches such as signature-tagged mutagenesis, some unexpected parallels as well as distinguishing features of microbial phenotypic acclimation in diverse environmental niches have surfaced. On the other hand, by the identification of a large proportion of genes with unknown function, these promoter-trapping studies underscore how little we know about the secret lives of bacteria and other microorganisms

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Section: Fun Genesmentioning

confidence: 84%

Unraveling the Secret Lives of Bacteria: Use of In Vivo Expression Technology and Differential Fluorescence Induction Promoter Traps as Tools for Exploring Niche-Specific Gene Expression

Rediers

Rainey

Vanderleyden

et al. 2005

Microbiol Mol Biol Rev

141

120

View full text Add to dashboard Cite

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“…Antigen localization within the Salmonella cell might also affect immune recognition, with accessible surface antigens being potentially more protective. However, the putative function of Mig-14 as a transcription factor (42) suggests that at least this partially protective antigen resides in the Salmonella cytoplasm. Surface localization can be directly determined by using proteome techniques (43), but this is difficult for ex vivo samples.…”

Section: Discussionmentioning

confidence: 99%

Antigen selection based on expression levels during infection facilitates vaccine development for an intracellular pathogen

Rollenhagen

Sörensen

Rizos

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

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Vaccines effective against intracellular pathogens could save the lives of millions of people every year, but vaccine development has been hampered by the slow largely empirical search for protective antigens. In vivo highly expressed antigens might represent a small attractive antigen subset that could be rapidly evaluated, but experimental evidence supporting this rationale, as well as practical strategies for its application, is largely lacking because of technical difficulties. Here, we used Salmonella strains expressing differential amounts of a fluorescent model antigen during infection to show that, in a mouse typhoid fever model, CD4 T cells preferentially recognize abundant Salmonella antigens. To identify a large number of natural Salmonella antigens with high expression levels during infection, we used a quantitative in vivo screening strategy. Immunization studies with five particularly attractive candidates revealed two highly protective antigens that might permit the development of an improved typhoid fever vaccine. In conclusion, we have established a rationale and an experimental strategy that will substantially facilitate vaccine development for Salmonella and possibly other intracellular pathogens.

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“…We examined the regulation and function of the Salmonella gene mig-14, which is dependent on PhoP for transcriptional activation within cultured macrophages (53) and contributes to oral virulence in mice (51). We demonstrate here that the mig-14 promoter is activated in minimal medium containing limiting concentrations of magnesium, low pH, or antimicrobial cationic peptides.…”

mentioning

confidence: 99%

“…In addition to restoring PB resistance with pmrD, we could also partially restore PB resistance to the mig-14 strain with a mig-14-expressing plasmid (data not shown). This plasmid had been previously used to complement the mig-14 mutant for virulence in oral infection of mice (51). mig-14 is not required for addition of 4-aminoarabinose to LPS.…”

mentioning

confidence: 99%

mig - 14 Is a Salmonella Gene That Plays a Role in Bacterial Resistance to Antimicrobial Peptides

et al. 2002

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It was previously demonstrated that the mig-14 gene of Salmonella enterica serovar Typhimurium is necessary for bacterial proliferation in the liver and spleen of mice following intragastric inoculation and that mig-14 expression, which is induced within macrophages, is under the control of the global regulator PhoP. Here we demonstrate that the mig-14 promoter is induced by growth in minimal medium containing low magnesium or acidic pH, consistent with regulation by PhoP. In addition, mig-14 is strongly induced by polymyxin B, protamine, and the mammalian antimicrobial peptide protegrin-1. While phoP is necessary for the induction of mig-14 in response to protamine and protegrin, mig-14 is still induced by polymyxin B in a phoP background. We also demonstrate that mig-14 is necessary for resistance of S. enterica serovar Typhimurium to both polymyxin B and protegrin-1. Gram-negative resistance to a variety of antimicrobial peptides has been correlated with modifications of lipopolysaccharide structure. However, we show that mig-14 is not required for one of these modifications, the addition of 4-aminoarabinose to lipid A. Additionally, sodium dodecyl sulfatepolyacrylamide gel electrophoresis analysis of wild-type and mig-14 lipopolysaccharide also shows no detectable differences between the two strains. Therefore, mig-14 contributes to Salmonella resistance to antimicrobial peptides by a mechanism that is not yet fully understood.

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mig-14Is a Horizontally Acquired, Host-Induced Gene Required forSalmonella entericaLethal Infection in the Murine Model of Typhoid Fever

Cited by 32 publications

References 38 publications

Unraveling the Secret Lives of Bacteria: Use of In Vivo Expression Technology and Differential Fluorescence Induction Promoter Traps as Tools for Exploring Niche-Specific Gene Expression

Unraveling the Secret Lives of Bacteria: Use of In Vivo Expression Technology and Differential Fluorescence Induction Promoter Traps as Tools for Exploring Niche-Specific Gene Expression

Antigen selection based on expression levels during infection facilitates vaccine development for an intracellular pathogen

mig - 14 Is a Salmonella Gene That Plays a Role in Bacterial Resistance to Antimicrobial Peptides

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