Dataset Information

Evolutionary trade-offs associated with loss of PmrB function in host-adapted Pseudomonas aeruginosa

ABSTRACT: Pseudomonas aeruginosa colonises the upper airway of cystic fibrosis (CF) patients, providing a reservoir of host-adapted genotypes that subsequently establish chronic lung infection. We previously experimentally-evolved P. aeruginosa in a murine model of respiratory tract infection and observed mutations in pmrB that promoted establishment and persistence of infection. Here we show that mutations in pmrB, which encodes the sensor kinase of the PmrAB two-component system, are acquired early in infection and increase resistance to the host antimicrobial lysozyme. Proteomic analysis of pmrB mutants reveal downregulation of proteins involved in LPS biosynthesis, antimicrobial resistance and phenazine production, and upregulation of proteins involved in adherence, lysozyme resistance and inhibition of the chloride ion channel CFTR, relative to wild-type strain LESB65. Accordingly, pmrB mutants show enhanced adherence to airway epithelial cells and downregulate host CFTR expression. P. aeruginosa pmrB mutations are found in CF patient isolates and are associated with the same phenotypes, but are subject to an evolutionary trade-off: enhanced colonisation potential, resistance to host defences and CFTR inhibition, but concomitant increased susceptibility to antibiotics.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Pseudomonas Aeruginosa

DISEASE(S): Cystic Fibrosis

SUBMITTER: Stuart Armstrong

LAB HEAD: Julian A. Hiscox

PROVIDER: PXD009705 | Pride | 2018-07-11

REPOSITORIES: Pride

ACCESS DATA

Publications

Evolutionary trade-offs associated with loss of PmrB function in host-adapted Pseudomonas aeruginosa.

Bricio-Moreno Laura L Sheridan Victoria H VH Goodhead Ian I Armstrong Stuart S Wong Janet K L JKL Waters Elaine M EM Sarsby Joscelyn J Panagiotou Stavros S Dunn James J Chakraborty Adrita A Fang Yongliang Y Griswold Karl E KE Winstanley Craig C Fothergill Joanne L JL Kadioglu Aras A Neill Daniel R DR

Nature communications 20180706 1

Pseudomonas aeruginosa colonises the upper airway of cystic fibrosis (CF) patients, providing a reservoir of host-adapted genotypes that subsequently establish chronic lung infection. We previously experimentally-evolved P. aeruginosa in a murine model of respiratory tract infection and observed early-acquired mutations in pmrB, encoding the sensor kinase of a two-component system that promoted establishment and persistence of infection. Here, using proteomics, we show downregulation of proteins ...[more]

PMID: 29980663

Similar Datasets

Project description:Cystic fibrosis (CF) is an inherited, multi-system disease caused by dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) protein, a ubiquitous ion channel important for epithelial hydration. A direct consequence of this dysfunction is impaired mucociliary clearance, chronic airway infection and a persistent neutrophilic inflammatory response that results in progressive loss of lung function, development of respiratory failure and premature death. Partial restoration of CFTR function is now possible for most CF patients through mutation specific CFTR modulators. Ivacaftor monotherapy produces significant clinical improvement in CF patients with the G511D mutation. Dual therapy, combining ivacaftor with lumacaftor or tezacaftor, results in modest clinical improvements in patients homozygous for F508del. More recently, triple therapy with elexacaftor/tezacaftor/ivacaftor (ETI) has led to dramatic improvements in lung function and quality of life in patients homozygous and heterozygous for F508del. Sputum proteomics is a powerful research technique capable of identifying important airway disease mechanisms by interrogating the proteome, an entire set of proteins within biological samples. It has confirmed the central role of neutrophilic immune dysregulation in CF and non-CF bronchiectasis, particularly involving the release of antimicrobial proteins and neutrophil-extracellular traps (NETs), and through impaired anti-inflammatory mechanisms. These processes produce distinct molecular signatures within the sputum proteome that become increasingly abnormal with chronic airway infection and progressive lung disease severity. In CF patients, airway and systemic inflammatory cytokines potentially related to these signatures reduce with the various forms of CFTR modulation. To date, no studies of ETI therapy in CF lung disease have assessed large-scale change in protein expression using untargeted proteomics. We hypothesised that ETI therapy would shift the sputum proteome toward health, potentially normalising airway biology in people with CF. The objectives of this study were to investigate changes in the CF sputum proteome with the introduction of ETI, correlate these with changes in clinical markers of disease severity, and make comparisons with the sputum proteome in healthy controls and in repeat samples from CF patients not suitable for ETI therapy. We also explored which molecular pathways associated with CF lung disease did not change with ETI.

Project description:Woody plant material represents a vast renewable resource that has the potential to produce biofuels and other bio-based products with favourable net CO2 emissions1,2. Its potential has been demonstrated in a recent study that generated novel structural materials from flexible mouldable wood3. The study of viral infection in plants has largely focussed on detrimental symptoms, such as leaf yellowing or cell death that result in reduced crop yields. Apple rubbery wood (ARW) disease is the result of a viral infection that causes woody stems to exhibit increased flexibility4. While ARW disease is associated with the presence of an RNA virus5 (ARWV), the mechanism underlying the development of its unique symptoms is not known. We demonstrate that ARWV symptoms arise from reduced lignification within the secondary cell wall of xylem fibres, while the mid-lamellae region and xylem ray cells are largely unaffected, and results in increased wood digestibility. Gene expression and proteomic data from symptomatic xylem clearly show the downregulation of phenylalanine ammonia lyase (PAL), the enzyme catalysing the first committed step in the phenylpropanoid pathway leading 2 to lignin biosynthesis. PAL downregulation is the likely cause of the decreased lignification, which is consistent with a large increase in soluble phenolics, including the lignin precursor phenylalanine, seen in symptomatic xylem. ARWV-infection results in the accumulation of many host-derived viral activated small interfering RNAs (vasiRNAs). PAL-derived vasiRNAs are among the most abundant vasiRNAs in symptomatic xylem and are likely the cause of reduced PAL activity. Apparently, the mechanism used by the virus to alter lignin exhibits similarities to the RNAi strategy that has been used to alter lignin in genetically modified trees to generate comparable improvements in wood properties6–8. CRISPR technology was recently used to increase yields in maize by introducing the naturally occurring waxy mutation into maize9. A similar biomimetic approach for biomass improvement based upon our understanding of ARWV symptoms offers a promising route to improve wood properties and provides important context for the genetic manipulation of trees.

Project description:To define the ECF sigma sigV - regulated genes during log growth phase in LB media under induction conditions for sigV The seven extracytoplasmic function (ECF) sigma (σ) factors of Bacillus subtilis are broadly implicated in resistance to antibiotics and other cell envelope stressors mediated, in part, by regulation of cell envelope synthesis and modification enzymes. We here define the regulon of σV as including at least 20 operons many of which are also regulated by σM, σX, or σW. The σV regulon is strongly and specifically induced by lysozyme and this induction is key to the intrinsic resistance of B. subtilis to lysozyme. Strains with null mutations in either sigV or in all seven ECF σ factor genes (Δ7ECF) have essentially equal increases in sensitivity to lysozyme. Induction of σV in the Δ7ECF background restores lysozyme resistance, whereas induction of σM, σX or σW does not. Lysozyme resistance results from the ability of σV to activate the transcription of two operons: the autoregulated sigV-rsiV-oatA-yrhK operon and dltABCDE. Genetic analyses reveal that oatA and dlt are largely redundant with respect to lysozyme sensitivity: single mutants are not affected in lysozyme sensitivity whereas a double oatA dltA mutant is as sensitive as a sigV null strain. Moreover, the triple sigV oatA dltA mutant is no more sensitive than the oatA dltA double mutant, indicating that there are no other σV-dependent genes necessary for lysozyme resistance. Thus, σV confers lysozyme resistance by activation of two cell wall modification pathways: O-acetylation of peptidoglycan catalyzed by OatA and D-alanylation of teichoic acids by DltABCDE. Strains Δ7Pxyl-sigV + xylose vs. Δ7Pxyl-sigV - xylose, 168 + lysozyme vs. 168 - lysozyme. Each experiment was conducted 6 times using three independent total RNA preparations (biologlical triplicates). For each paired comparison, one sample was labeled with Alexa Fluor 555 and the other was with Alexa Fluor 647. For each comparison, three replicates were performed with dyeswap with the same RNA preparation.

Project description:Dysfunction of the cystic fibrosis transmembrane regulator (CFTR) in cystic fibrosis (CF) results in exaggerated and chronic inflammation as well as increased susceptibility to chronic pulmonary infections, in particular with Pseudomonas aeruginosa. Based on the concept that host immune responses do not seem to be adequate to eradicate P.aeruginosa from the lungs of CF patients and that dendritic cells (DC) play an important role in initiating and shaping adaptive immune responses, this study analyzed the role of CFTR in bone marrow-derived murine DC from CFTR knockout (CF) mice with and without exposure to P.aeruginosa. DC expressed CFTR mRNA and protein, although at much lower levels compared to whole lung. Microarray analysis of gene expression levels in DC generated from CF and wild type (WT) mice revealed significantly different expression of 16 genes in CF DC compared to WT DC. Among the genes with lower expression in CF DC was Caveolin-1, a membrane lipid raft protein. Messenger RNA and protein levels of Caveolin-1 were decreased in the CF DC compared to WT DC. Consistently, the active form of sterol-responsive element binding protein (SREBP), a negative regulator of Caveolin-1 expression, was increased in CF DC. Following exposure to P.aeruginosa, gene expression levels in CF and WT DC changed for 912 genes involved in inflammation, chemotaxis, signaling, cell cycling and apoptosis more than 1.5-fold. Among the genes that showed a different response between WT and CF DC infected with P.aeruginosa, were 3Î²-hydroxysterol-Î7 reductase (Dhcr7) and stearoyl-CoA desaturase 2 (Scd2), two enzymes involved in the lipid metabolism that are also regulated by SREBP. These results suggest that CFTR dysfunction in non-epithelial cells results in changes in the expression of genes encoding factors involved in membrane structure and lipid-metabolism. These membrane alterations in immune cells may contribute to the abnormal inflammatory and immune response characteristic of CF. Experiment Overall Design: comparison of gene expression in dendritic cells of cystic fibrosis mice without or with Pseudosmonas aeruginosa infection vs wild type dendritic cell controls

Dataset Information

Evolutionary trade-offs associated with loss of PmrB function in host-adapted Pseudomonas aeruginosa

Publications

Evolutionary trade-offs associated with loss of PmrB function in host-adapted Pseudomonas aeruginosa.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure