Bacterial host-adaptation during experimental infection
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PROVIDER: PRJEB34658 | ENA |
REPOSITORIES: ENA
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Project description:Human activity is altering the environment at a rapid pace, challenging the adaptive capacities of genetic variation within animal populations. Animals also harbor extensive gut microbiomes, which play diverse roles in host health and fitness and may help expanding host capabilities. The unprecedented scale of human usage of xenobiotics and contamination with environmental toxins describes one challenge against which bacteria with their immense biochemical diversity are particularly suited to offer solutions. To explore the paths leading to bacteria-assisted rapid adaptation, we used Caenorhabditis elegans harboring a defined microbiome, and the antibiotic neomycin as a model toxin, harmful for the worm host and neutralized to different extents by microbiome members. Worms exposed to neomycin showed delayed development and decreased survival but were protected when colonized by neomycin-resistant members of the microbiome. Through a combination of 16S gene sequencing, counting of live bacteria and behavioral assays we identified two distinct mechanisms that facilitated adaptation: gut enrichment for a neomycin-modifying strain driven by altered bacterial competition; and host avoidance behavior, which depended on the stress-activated KGB-1/JNK and enabled preference of neomycin-protective bacteria. The straightforwardness of these mechanisms suggests that bacteria-assisted host adaptation may be more common than currently appreciated, protecting animals from novel stressors. However, gut remodeling may also cause dysbiosis, and additional experiments identified fitness trade-offs including increased susceptibility to infection as well as metabolic remodeling. Extending these results to other toxins suggests yet unaccounted-for microbiome-dependent long-term consequences of toxin exposure.
2023-11-09 | GSE246966 | GEO
Project description:Current therapeutic strategies against bacterial infections focus on reduction of pathogen load using antibiotics; however, stimulation of host tolerance to infection in the presence of pathogens might offer an alternative approach. We used computational transcriptomics and Xenopus laevis embryos to discover infection response pathways, identify potential tolerance inducer drugs, and validate their ability to induce broad tolerance. Xenopus exhibits natural tolerance to Acinetobacter baumanii, Klebsiella pneumoniae, Staphylococcus aureus, and Streptococcus pneumoniae bacteria, whereas Aeromonas hydrophila and Pseudomonas aeruginosa produce lethal infections. Transcriptional profiling led to definition of a 20-gene signature that discriminates between tolerant and susceptible states, as well as identification of a more active tolerance response to gram negative compared to gram positive bacteria. Gene pathways associated with active tolerance in Xenopus, including some involved in metal ion binding and hypoxia, were found to be conserved across species, including mammals, and administration of a metal chelator (deferoxamine) or a HIF-1 agonist (1,4-DPCA) in embryos infected with lethal A. hydrophila increased survival despite high pathogen load. These data demonstrate the value of combining the Xenopus embryo infection model with computational multi-omics analyses for mechanistic discovery and drug repurposing to induce host tolerance to bacterial infections.
2022-06-16 | GSE196424 | GEO
Project description:Current therapeutic strategies against bacterial infections focus on reduction of pathogen load using antibiotics; however, stimulation of host tolerance to infection in the presence of pathogens might offer an alternative approach. We used computational transcriptomics and Xenopus laevis embryos to discover infection response pathways, identify potential tolerance inducer drugs, and validate their ability to induce broad tolerance. Xenopus exhibits natural tolerance to Acinetobacter baumanii, Klebsiella pneumoniae, Staphylococcus aureus, and Streptococcus pneumoniae bacteria, whereas Aeromonas hydrophila and Pseudomonas aeruginosa produce lethal infections. Transcriptional profiling led to definition of a 20-gene signature that discriminates between tolerant and susceptible states, as well as identification of a more active tolerance response to gram negative compared to gram positive bacteria. Gene pathways associated with active tolerance in Xenopus, including some involved in metal ion binding and hypoxia, were found to be conserved across species, including mammals, and administration of a metal chelator (deferoxamine) or a HIF-1 agonist (1,4-DPCA) in embryos infected with lethal A. hydrophila increased survival despite high pathogen load. These data demonstrate the value of combining the Xenopus embryo infection model with computational multi-omics analyses for mechanistic discovery and drug repurposing to induce host tolerance to bacterial infections.
2022-06-16 | GSE196422 | GEO
Project description:In this study, we use mass spectrometry (MS)-based proteomics to define the host response under single and dual infection states of macrophages with C. neoformans and K. pneumoniae to define critical responses of each biological system. This high-resolution comparative analysis illustrates how protein abundance deviates during a transition from an acute to chronic infectious state with exposure to additional microbial stimuli. We reveal global changes upon infection followed by pathogen-specific host response signatures. Additionally, we define regulatory changes within C. neoformans as the fungi adapts to the host environment and stabilizes prior to further disruption in the presence of chronic bacterial infection. We validate our findings with host cytokine detection and phenotypic profiling of the fungi throughout the host and bacterial exposures. Overall, our study provides an in-depth analysis of cross-kingdom protein level changes during macrophage infection. This information provides new insight into fungal modulation of the immune response, including a stabilization and adaptation of the host and fungi during a chronic infection, which is disrupted upon chronic co-infection with a bacterial pathogen.
2022-06-30 | PXD033393 | Pride
Project description:Consecutive exposures to different pathogens are very common and often alter host immune responses. Yet, it remains unknown how a secondary bacterial infection interferes with an ongoing adaptive immune response elicited against primary invading pathogens. Here, we demonstrate that pre-existing germinal center (GC) B cells are incapable of enduring radical metabolic changes induced by recruited Sca-1+ monocytes during Salmonella Typhimurium (STm) infection. GCs-induced by influenza, plasmodium and commensals deteriorated upon STm infection. GC collapse was independent of direct bacterial interactions with B cells, but rather, was induced through recruitment of CCR2-dependent Sca-1+ monocytes. GC collapse was dependent on non-B cell TLR-4, TNFα and IFNγ, which was essential for Sca-1+ monocyte differentiation in the bone-marrow. Monocyte recruitment and GC disruption also occurred during LPS-supplemented vaccination and Listeria monocytogenes infection. Thus, systemic activation of the innate immune response upon lethal bacterial infection is induced at the expense of antibody-mediated immunity.
2022-11-02 | GSE188474 | GEO
Project description:Bacterial adaptation involves extensive cellular reorganization. In particular, growth rate adjustments are associated with substantial modifications of gene expression and mRNA abundance. In this work we aimed to assess the role of mRNA degradation during such variations. A genome-wide transcriptomic-based method was used to determine mRNA half-lives. The model bacterium Lactococcus lactis was used and five growth rates were studied in continuous cultures under isoleucine-limitation and in batch cultures during the adaptation to the isoleucine starvation. During continuous isoleucine-limited growth, the mRNAs of different genes had different half-lives. The stability of most of the transcripts was not constant, and increased as the growth rate decreased. This half-life diversity was analyzed to investigate determinants of mRNA stability. The concentration, length, codon adaptation index and secondary structures of mRNAs were found to contribute to the regulation of mRNA stability in these conditions. However, the growth rate was, by far, the most influential determinant. The respective influences of mRNA degradation and transcription on the regulation of intra-cellular transcript concentration were estimated. The role of degradation on mRNA homeostasis was clearly evidenced: for more than 90 % of the mRNAs studied during continuous isoleucine-limited growth of L. lactis, degradation was antagonistic to transcription. Although both transcription and degradation had, opposite effects,, the mRNA changes in response to growth rate were driven by transcription. Interestingly, degradation control increased during the dynamic adaptation of bacteria as the growth rate reduced due to progressive isoleucine starvation in batch cultures. This work shows that mRNA decay differs between gene transcripts and according to the growth rate. It demonstrates that mRNA degradation is an important regulatory process involved in bacterial adaptation. However, its impact on the regulation of mRNA levels is smaller than that of transcription in the conditions studied. In the study presented here mRNA stabilities were analyzed at 5 growth rates. For each growth rate mRNA levels were measured in a time course experiment following rifampicin addition. At least 12 time points per growth rate are available, including 3 replicates of the zero.
2014-06-16 | E-GEOD-43875 | biostudies-arrayexpress
Project description:Bacterial adaptation involves extensive cellular reorganization. In particular, growth rate adjustments are associated with substantial modifications of gene expression and mRNA abundance. In this work we aimed to assess the role of mRNA degradation during such variations. A genome-wide transcriptomic-based method was used to determine mRNA half-lives. The model bacterium Lactococcus lactis was used and five growth rates were studied in continuous cultures under isoleucine-limitation and in batch cultures during the adaptation to the isoleucine starvation. During continuous isoleucine-limited growth, the mRNAs of different genes had different half-lives. The stability of most of the transcripts was not constant, and increased as the growth rate decreased. This half-life diversity was analyzed to investigate determinants of mRNA stability. The concentration, length, codon adaptation index and secondary structures of mRNAs were found to contribute to the regulation of mRNA stability in these conditions. However, the growth rate was, by far, the most influential determinant. The respective influences of mRNA degradation and transcription on the regulation of intra-cellular transcript concentration were estimated. The role of degradation on mRNA homeostasis was clearly evidenced: for more than 90 % of the mRNAs studied during continuous isoleucine-limited growth of L. lactis, degradation was antagonistic to transcription. Although both transcription and degradation had, opposite effects,, the mRNA changes in response to growth rate were driven by transcription. Interestingly, degradation control increased during the dynamic adaptation of bacteria as the growth rate reduced due to progressive isoleucine starvation in batch cultures. This work shows that mRNA decay differs between gene transcripts and according to the growth rate. It demonstrates that mRNA degradation is an important regulatory process involved in bacterial adaptation. However, its impact on the regulation of mRNA levels is smaller than that of transcription in the conditions studied.
2014-06-16 | GSE43875 | GEO
Project description:Consecutive exposures to different pathogens are very common and often alter host immune responses. Yet, it remains unknown how a secondary bacterial infection interferes with an ongoing adaptive immune response elicited against primary invading pathogens. Here, we demonstrate that pre-existing germinal center (GC) B cells are incapable of enduring radical metabolic changes induced by recruited Sca-1+ monocytes during Salmonella Typhimurium (STm) infection. GCs-induced by influenza, plasmodium and commensals deteriorated upon STm infection. GC collapse was independent of direct bacterial interactions with B cells, but rather, was induced through recruitment of CCR2-dependent Sca-1+ monocytes. GC collapse was dependent on non-B cell TLR-4, TNFα and IFNγ, which was essential for Sca-1+ monocyte differentiation in the bone-marrow. Monocyte recruitment and GC disruption also occurred during LPS-supplemented vaccination and Listeria monocytogenes infection. Thus, systemic activation of the innate immune response upon lethal bacterial infection is induced at the expense of antibody-mediated immunity.
2022-11-02 | GSE188475 | GEO
Project description:Comparative genomics of 800 Staphylococcus aureus isolates from different host species
| PRJEB20741 | ENA
Project description: Not available
| S-EPMC4985009 | biostudies-other