Response of Pseudomonas aeruginosa to the innate immune system-derived oxidants hypochlorous acid and hypothiocyanous acid
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PROVIDER: PRJNA511884 | ENA |
REPOSITORIES: ENA
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Project description:Purpose: The aim of this study was to determine the transcriptional response of P. aeruginosa PA14 to HOCl and HOSCN stress, and determine genes dependent on RclR (PA14_07340) regulation. Methods: PA14 WT and ∆rclR exponential phase cultures were exposed to sub-lethal amounts of HOCl or HOSCN (2.2 or 0.8 mM, respectively), or untreated, and after 20 minutes of exposure, RNA was extracted and gene expression analysed by RNA-seq. Reads Per Kilobase per Million mapped reads (RPKM) were determined and the log2 fold change of the RPKM values of treated WT compared to untreated WT, or treated WT compared to treated ∆rclR was calculated. Genes with a log2 fold change of >1.5 were considered upregulated and genes with a log2 fold change of <-1.5 were considered downregulated. Results: In the WT strain, HOCl exposure resulted in upregulation of 231 genes and downregulation of 20 genes, and HOSCN exposure caused upregulation of 105 genes and downregulation of 16 genes. There was considerable overlap in the transcriptional response to HOCl and HOSCN, with 74 genes being induced in response to both oxidants. Genes upregulated by HOCl and HOSCN included those involved in sulphur and taurine transport, those encoding the type 3 secretion system, the MexEF-OprN drug efflux pump, and the putative peroxiredoxin RclX (PA14_07355). Comparison of the treated WT and treated ∆rclR strains revealed that in the presence of HOCl RclR upregulated 42 genes and downregulated 7 genes, and in the presence of HOSCN upregulated 132 genes and downregulated 213 genes. In the presence of both HOCl and HOSCN, RclR was required for upregulation of rclX as well as pyocyanin biosynthesis genes. In the presence of HOSCN, RclR downregulated a large number of genes, including those encoding chaperones. Conclusions: Our data have identified that the transcriptional response of P. aeruginosa to HOCl and HOSCN is multifaceted and appears to be linked to antibiotic resistance and the virulence factors pyocyanin and type 3 secretion. Determination of the regulon of the transcriptional regulator RclR after HOCl and HOSCN exposure suggests RclR has a role in coordinating the P. aeruginosa response to these oxidants.
2020-11-02 | GSE124385 | GEO
Project description:To establish infections in human hosts, P. aeruginosa must overcome innate immune generated oxidative stress, such as the hypochlorous acid (HOCl) produced by neutrophils. We set out to find specific metabolomic biomarkers of oxidative stress and we developed a protocol for the metabolic profiling of P. aeruginosa cultures grown in the presence of different oxidants using a novel ionisation technique for mass spectrometry, laser-desorption rapid evaporative ionisation mass spectrometry (LD-REIMS). We demonstrate the ability of LD-REIMS to classify samples as untreated or treated with a specific oxidant with 100 % accuracy and identified a panel of 54 metabolites with significantly altered concentrations after exposure to one or more of the oxidants. Key metabolic changes were conserved in P. aeruginosa clinical strains isolated from patients with cystic fibrosis lung infections. These data demonstrate that HOCl stress impacted the Pseudomonas Quinolone Signal (PQS) quorum sensing system. Ten 2-alkyl-4-quinolones (AHQs) associated with the PQS system were significantly lower in concentration in HOCl-stressed P. aeruginosa cultures, including 2-heptyl-3-hydroxy-4(1H)-quinolone (PQS), the most active signal molecule of the PQS system. The PQS system regulates the production of virulence factors, including pyocyanin and elastase, and their levels were markedly affected by HOCl stress. No pyocyanin was detectable and elastase concentrations were significantly reduced in cultures grown with sub-lethal concentrations of HOCl, suggesting that this neutrophil-derived oxidant may disrupt the ability of P. aeruginosa to establish infections through interference with production of PQS-associated virulence factors.
2023-10-06 | MSV000093056 | MassIVE
Project description:Inflammatory diseases of the gut are associated with increased intestinal oxygen concentrations and high levels of inflammatory oxidants, including hydrogen peroxide (H2O2) and hypochlorous acid (HOCl), which are antimicrobial compounds produced by the innate immune system. This contributes to dysbiotic changes in the gut microbiome, including increased populations of pro-inflammatory enterobacteria (Escherichia coli and related species) and decreased levels of health-associated anaerobic Firmicutes and Bacteroidetes. The pathways for H2O2 and HOCl resistance in E. coli have been well-studied, but little is known about how commensal and probiotic bacteria respond to inflammatory oxidants. In this work, we have characterized the transcriptomic response of the anti-inflammatory, gut colonizing Gram-positive probiotic Lactobacillus reuteri to both H2O2 and HOCl. L. reuteri mounts distinct responses to each of these stressors, and both gene expression and survival were strongly affected by the presence or absence of oxygen. Oxidative stress response in L. reuteri required several factors not found in enterobacteria, including the small heat shock protein Lo18, polyphosphate kinase 2, and RsiR, an L. reuteri-specific regulator of anti-inflammatory mechanisms. These results raise the intriguing possibility of developing treatments for inflammatory gut diseases that could sensitize pro-inflammatory enterobacteria to killing by the immune system while sparing anti-inflammatory, health-associated species.
2019-08-15 | GSE127961 | GEO
Project description:Acid ceramidase regulates innate immune memory
| PRJNA779737 | ENA
Project description:Staphylococcus aureus strain MW2 was exposed to the following neutrophil microbicides, hydrogen peroxide (H2O2), hypochlorous acid (HOCl) and azurophilic granule proteins. At the indicated time points, bacterial cultures were centrifuged and bacteria were lysed with RLT buffer (Qiagen) using a FastPrep system. Purification of MW2 RNA and subsequent preparation of labeled cDNA target was performed as described in Methods. Labeling of samples, GeneChip hybridization and scanning were performed according to standard Affymetrix protocols. Experiments were performed in triplicate, using three bacterial cultures from separate days for each treatment. These analyses provide an enhanced view of the mechanisms used by CA-MRSA to circumvent destruction by the human innate immune system. 48 samples total: MW2 with the following treatments, untreated, GP (azurophilic granule proteins), H2O2 (hydrogen peroxide) or HOCl (hypochlorous acid) at 4 time points in triplicate
2010-05-26 | E-GEOD-6716 | biostudies-arrayexpress
Project description:Hypochlorous acid (HOCl) is a potent oxidant that is produced endogenously in mammalian tissue by phagocytes. Exogenous exposure to HOCl also can occur following inhalation of chlorine gas. HOCl has been implicated as a source of oxidative stress associated atherosclerosis and other diseases. The purpose of this study was to identify dose-dependent transitions in cellular response to hypochlorous acid (HOCl), with a focus on understanding how various cellular defense and stress dose-responses overlap.
2009-04-01 | GSE15457 | GEO
Project description:Bacterial interspecies interactions shape the function and structural dynamics of microbial communities and affect disease progression of polymicrobial infections. Here, we present data suggesting that the FemA-FemR-FemI (Fem) cell surface signaling system in P. aeruginosa serves as an interspecies signaling pathway between P. aeruginosa and Mycobacterium species. The Fem system is regulated by the type three secretion system (T3SS) regulator ExsA. Fem system significantly influenced virulence factors in P. aeruginosa, including the quorum sensing systems, pyocyanin production, biofilm formation and the type six secretion systems (T6SSs). Our study using a Galleria mellonella infection model indicates femA deletion significantly increased the host survival rate while femI over-expression decreased it, demonstrating that the Fem system’s role in bacterial pathogenicity in vivo. We propose that the Fem system functions as an interspecies signaling pathway enabling P. aeruginosa to alter its behaviours in response to the presence of mycobacteria.
2021-01-14 | GSE164773 | GEO
Project description:Oxygenated unsaturated fatty acids, known as oxylipins, are signaling molecules commonly used for cell-to-cell communication in eukaryotes. However, a role for oxylipins in mediating communication in prokaryotes has not previously been described. Bacteria mainly communicate via quorum sensing (QS) , which involves the production and detection of diverse small molecules termed autoinducers. We showed that oleic acid-derived oxylipins 10-HOME and 7,10-DiHOME produced by Pseudomonas aeruginosa function as autoinducers of a novel quorum sensing system termed Oxylipin-Dependent QS Sytem (ODS). This experiment was designed to determine the genes whose expression is altered by these P. aeruginosa oxylipins. We found that the ODS system controls the cell density-dependent expression of a P. aeruginosa gene subset through the mediation of 10-HOME and 7,10-DiHOME oxylipins.
2018-12-05 | GSE123356 | GEO
Project description:The Pseudomonas aeruginosa MvfR-dependent QS regulatory pathway controls the expression of key virulence genes; and is activated via the extracellular signals 4-hydroxy-2-heptylquinoline (HHQ) and 3,4-dihydroxy-2-heptylquinoline (PQS), whose syntheses depend on anthranilic acid (AA), the primary precursor of 4-hydroxy-2-alkylquinolines (HAQs). We identified halogenated AA analogs that specifically inhibited HAQ biosynthesis and disrupted MvfR-dependent gene expression. These compounds restricted P. aeruginosa systemic dissemination and mortality in mice, without perturbing bacterial viability, and inhibited osmoprotection, a widespread bacterial function.
2009-07-17 | GSE17111 | GEO
Project description:The ability of Pseudomonas aeruginosa to detect host immune responses and coordinate the production of virulence factors is crucial for its high pathogenicity. However, the regulatory mechanisms underlying this process remain largely unknown. In this study, we extensively characterize the conserved two-component system CprRS in P. aeruginosa and uncover the role of the sensor histidine kinase CprS as a receptor for the human host defense peptide LL-37, thereby modulating bacterial virulence. In the presence of LL-37, CprS functions as a phosphatase, targeting the intracellular activator CprR for phosphorylation at position D53, ultimately leading to CprR activation. By employing quantitative proteomics and transcription analysis, we further elucidate that CprR induction under LL-37 treatment promotes the expression of type III secretion system effectors. This, in turn, impedes the expression of proinflammatory cytokines and significantly increases bacterial cytotoxicity towards macrophages. Notably, the mutation of either cprS or cprR markedly diminishes bacterial survival in both macrophage and insect infection models. Collectively, our study uncovers a novel regulatory mechanism of the two-component system in P. aeruginosa, which enables the bacterium to sense and respond to human innate immune system responses while ensuring a timely balance of virulence genes.
2023-05-25 | PXD042487 |