Browse
Submit Data
Databases
API
Help

Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Transcription profiling by array of E. coli NCTC 9001 challenged with four different cationic antimicrobial peptides

ABSTRACT: Obtaining an in depth understanding of the arms races between peptides comprising the innate immune response and bacterial pathogens is of fundamental interest and will inform the development of new antibacterial therapeutics. Many cationic antimicrobial peptides (AMPs) share a range of structural and physical features that have been linked to antibacterial activity and yet they vary dramatically in their potency towards the same bacterial target. We hypothesised that a whole organism view of AMP challenge on Escherichia coli could provide a sophisticated, bacterial perspective enabling understanding of how potency is linked to mode of action. We used a 1H NMR metabolomic approach to characterise the effect on E. coli of challenge with four structurally and physically related AMPs: magainin 2, pleurocidin, buforin II and a designed peptide comprising D-amino acids only. Sub-inhibitory conditions, where these peptides nevertheless induced a bacterial response, were identified enabling electron microscopic and transcriptomic analyses. Although some common features of the bacterial response to AMP challenge could be identified, the metabolomes, morphological changes and the vast majority of the changes in gene expression were specific to each AMP. We show the antibacterial mode of action of AMPs can be accurately predicted by comparing ontological profiles generated by transcriptomic analyses. The response of E. coli to AMP challenge is highly plastic, with the bacteria capable of deploying a multifaceted response adapted to the mode of action rather than the physical properties of the AMP.

ORGANISM(S): Escherichia coli

SUBMITTER: Justyna Kozlowska

PROVIDER: E-MTAB-1703 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Json Xml

Similar Datasets

High-throughput discovery of human antimicrobial peptide activators of Salmonella Typhimurium PhoPQ

Project description:We developed a surface-displayed library of 117 human antimicrobial peptides (AMPs) and over 3000 human AMP variants in a laboratory E. coli strain expressing PhoP and PhoQ from Salmonella Typhimurium. We used sort-seq (fluorescence-activated cell sorting followed by next-generation sequencing) to characterize PhoPQ activation by these surface-displayed AMPs.

2022-11-09 | GSE174191 | GEO

Identification and characterization of CC-AMP1-like and CC-AMP2-like peptides in Capsicum spp.

Project description:Antimicrobial peptides (AMPs) are compounds with a variety of bioactive properties. Especially promising are their antibacterial activities, often towards drug-resistant pathogens. Across different AMP sources, AMPs expressed within plants are relatively underexplored, with a limited number of plant AMP families identified. Recently, we identified the novel AMPs CC-AMP1 and CC-AMP2 in ghost pepper plants (Capsicum chinense x frutescens), exerting promising antibacterial activity and not classifying into any known plant AMP family. Herein, AMPs related to CC-AMP1 and CC-AMP2 were identified within both Capsicum annuum and Capsicum baccatum. Targeted MS/MS experiments were performed to determine peptide sequences, guided by in silico AMP sequence predictions.

2024-01-27 | PXD041035 | Pride

High level resistance to the antimicrobial peptide TAT-RasGAP (317-326) results from sequential acquisition of mutations influencing the Escherichia coli cell envelope biogenesis and composition

Project description:Antimicrobial peptides (AMPs) are promising alternatives to classical antibiotics against antibiotic-resistant pathogens. TAT-RasGAP (317-326) is an AMP with broad range antibacterial activity, but its mechanism of action is unknown. Escherichia coli can become partially resistant to TAT-RasGAP (317-326) in vitro. In this study, we analysed a strain of E. coli with extensive resistance to TAT-RasGAP (317-326) but not to other AMPs that we obtained after twenty passages during an in vitro resistance selection experiment. This strain accumulates four mutations, that all apparently affect bacterial envelope composition. One of these mutations is a point mutation in bamA, which encodes an essential protein involved in the folding and proper insertion of outer membrane proteins. The point mutation resulted in a charge change in an area of the protein corresponding to a negatively charged loop at the surface of BamA. Using CRISPR-Cas9-based targeted mutagenesis, we showed that mutations lowering the negative charge of this loop decreased sensitivity of E. coli to TAT-RasGAP (317-326). In silico simulations unveiled the molecular driving forces responsible for the interaction between TAT-RasGAP (317-326) and BamA. These results indicated that electrostatic interactions, particularly hydrogen bonds, are involved in the stability of the molecular complex, representing a predictive fingerprint of the TAT-RasGAP (317-326) - BamA interaction strength. Interestingly, BamA activity was not affected by TAT-RasGAP (317-326), indicating that BamA may function as a specific receptor for this AMP. Our results indicate that binding and entry of TAT-RasGAP (317-326) may involve different mechanisms compared to other AMPs, which is in line with limited cross-resistance observed between different AMPs. This limited cross-resistance is important for the clinical application of AMPs towards drug-resistant pathogens.

2024-12-02 | PXD055766 | Pride

Regulation of Antimicrobial Peptides in Hermetia illucens in Response to Fungal Exposure

Project description:The black soldier fly (Hermetia illucens) is important in antimicrobial peptides (AMP) research due to its exposure to diverse microbial environments. However, the impact of different fungal exposures on AMP abundance in H. illucens has not been thoroughly explored. Our study focused on basal conditions and interactions with three fungi: the non-pathogenic Candida tropicalis (isolated from larval gut), Saccharomyces cerevisiae, and the pathogenic Beauveria bassiana. Using RNA-seq and LC-MS/MS, we found that under standard conditions, the majority of AMPs belonged to the Lysozyme, Cecropin, and Defensin classes, with Defensins exhibiting the highest quantification levels. Exposure to any of the fungi upregulated AMP gene expression, indicating immune activation. Notably, exposure to C. tropicalis and B. bassiana led to notable downregulation of AMPs in H. illucens larvae compared to S. cerevisiae, suggesting these fungi may suppress or modulate the host immune response to aid their survival and colonization. The immune response of H. illucens larvae revealed that S. cerevisiae and B. bassiana trigger similar AMP pathways, whereas C. tropicalis elicits a distinct response with upregulation of Defensins and Cecropins. Lysozymes, known for their antibacterial and antifungal activity, were upregulated in response to S. cerevisiae and B. bassiana, but downregulated with C. tropicalis, potentially facilitating fungal survival in the larvae’s gut. This suggests that C. tropicalis adapts to reduce immune pressure, while B. bassiana may suppress AMPs to persist. Understanding these mechanisms opens possibilities for leveraging AMPs in combating C. tropicalis, which is implicated in human diseases.

2024-11-19 | GSE272202 | GEO

Development of gene expression signatures for murine bladder: Control vs. UTI89

Project description:Antimicrobial peptides (AMPs) serve key proposed roles in defending the urinary tract against invading uropathogens, but individual AMPs bearing greatest responsibility for these functions remain largely unknown. We identified RegIIIγ as the most transcriptionally upregulated AMP in bladder transcriptomes following uropathogenic Escherichia coli (UPEC) infection. We confirmed induction of RegIIIγ mRNA during cystitis and pyelonephritis by quantitative RT-PCR. Immunoblotting demonstrates increased bladder and urinary RegIIIγ protein levels following UPEC infection. Immunostaining localizes RegIIIγ protein to urothelial cells of infected bladders and kidneys. Human patients with cystitis and pyelonephritis exhibit increased urine levels of the orthologous HIP/PAP protein. Recombinant RegIIIγ protein does not demonstrate bactericidal activity toward UPEC in vitro, but does kill Staphylococcus saprophyticus in a dose-dependent manner. RegIIIγ knockout and control urinary tracts contain comparable bacterial burden following experimental inoculation of UPEC as well as Gram-positive uropathogens. Thus, while RegIIIγ and HIP/PAP expression occurs in human and murine UTI, their specific functions in the urinary tract remain uncertain.

2015-12-29 | GSE72007 | GEO

Antimicrobial resistance of Staphylococcus aureus by quantitative proteomics with TMT-labelling

Project description:The clinical development of antimicrobial peptides (AMPs) is currently under evaluation to combat the rapid increase in multi-drug resistant bacterial pathogens. However, many AMPs closely resemble components of the human innate immune system, and the ramifications of prolonged bacterial exposure to AMPs are not fully understood. Here we show that in vitro serial passage of a clinical USA300 methicillin-resistant Staphylococcus aureus strain in a host-mimicking environment containing host-derived AMPs results in the selection of stable AMP-resistance. AMP-resistant S. aureus mutants often displayed little to no fitness cost and caused invasive disease in mice. Further, this phenotype coincided with diminished susceptibility to both clinically prescribed antibiotics and human defense peptides. These findings suggest that therapeutic use of AMPs could select for virulent mutants with cross-resistance to human innate immunity as well as antibiotic therapy. Thus, therapeutic use of AMPs and the implications of cross-resistance need to be carefully monitored and evaluated.

2016-09-26 | PXD004036 | Pride

Mass spectrometric identification of antimicrobial peptides from medicinal seeds

Project description:Traditional medicinal plants contain a variety of bioactive natural products including cysteine-rich (Cys-rich) antimicrobial peptides (AMPs). Cys-rich AMPs are often crosslinked by multiple disulfide bonds which increase their resistance to chemical and enzymatic degradation. However, this class of molecules is relatively underexplored. Herein, in silico analysis predicted 80 – 100 Cys-rich AMPs per species from three edible traditional medicinal plants: Linum usitatissimum (flax), Trifolium pratense (red clover), and Sesamum indicum (sesame). Proteomics analysis of seed peptide extracts revealed direct evidence for the translation of 3-10 Cys-rich AMPs per species including lipid transfer proteins, defensins, α-hairpinins, and snakins. Negative activity revealed by antibacterial screening highlights the importance of employing a multi-pronged approach for AMP discovery. Further, this study demonstrates that flax, red clover, and sesame are promising sources of further AMP discovery and characterization.

2022-02-16 | PXD029289 | Pride

E. coli acquires specific resistance to the antimicrobial peptide TAT-RasGAP (317-326) via modification of charge at the surface of the essential outer membrane insertase BamA

Project description:Antimicrobial peptides (AMPs) are promising alternatives to classical antibiotics against multidrug resistant pathogens. TAT-RasGAP (317-326) is an AMP with broad range antibacterial activity, but its mechanism of action is unknown. Escherichia coli can become partially resistant to TAT-RasGAP (317-326) in vitro when passaged eight times with increasing concentrations of this peptide via mutations of the two-component system EnvZ/OmpR. To test whether additional mutations can cause further increase in resistance, we analysed a strain of E. coli showing high level of specific resistance to TAT-RasGAP (317-326) that we obtained after twenty passages of in vitro resistance selection. This strain bears, in addition to an envZ point mutation, a point mutation in bamA, an essential gene encoding an insertase involved in the insertion of outer membrane proteins. This mutation modifies the charge in a negatively charged loop (Q495-T505) at the surface of BamA. In silico docking simulations predict that binding affinity between TAT-RasGAP (317-326) and BamA varies depending on the charge of the Q495-T505 loop. We show here using CRISPR-Cas9-based targeted mutagenesis that mutations lowering the negative charge of the Q495-T505 loop decrease sensitivity of E. coli to TAT-RasGAP (317-326). Interestingly, BamA activity was not affected by TAT-RasGAP (317-326), indicating that BamA may function as a specific receptor for the AMP TAT-RasGAP (317-326). Our results indicate that binding and entry of TAT-RasGAP (317-326) may involve different mechanisms compared to other AMPs, which is in line with limited cross-resistance observed between different AMPs. This limited cross-resistance is important for the clinical application of AMPs towards multidrug resistant pathogens.

2024-12-02 | PXD051962 | Pride

Dengue virus inhibits immune responses in Aedes aegypti cells

Project description:The ability of many viruses to manipulate the host antiviral immune response often results in complex host-pathogen interactions. In order to study the interaction of dengue virus (DENV) with the Aedes aegypti immune response, we have characterized the DENV infection-responsive transcriptome of the immune-competent A. aegypti cell line Aag2. As in mosquitoes, DENV infection transcriptionally activated the cell line Toll pathway and a variety of cellular physiological systems. Most notably, however, DENV infection down-regulated the expression levels of numerous immune signaling molecules and antimicrobial peptides (AMPs). Functional assays showed that transcriptional induction of AMPs from the Toll and IMD pathways in response to bacterial challenge is impaired in DENV-infected cells. In addition, Escherichia coli, a gram-negative bacteria species, grew better when co-cultured with DENV-infected cells than with uninfected cells, suggesting a decreased production of AMPs from the IMD pathway in virus-infected cells. Pre-stimulation of the cell line with gram-positive bacteria prior to DENV infection had no effect on DENV titers, while pre-stimulation with gram-negative bacteria resulted in an increase in DENV titers. These results indicate that DENV is capable of actively suppressing immune responses in the cells it infects, a phenomenon that may have important consequences for virus transmission and insect physiology. Infected (dengue virus or heat-inactivated dengue virus) vs. naive cells. 3 replicates each.

2011-10-31 | E-GEOD-33274 | biostudies-arrayexpress

Fungal peptide destruxin a plays a specific role in suppressing the innate immune response in Drosophila melanogaster

Project description:Destruxins are a class of insecticidal, anti-viral and phytotoxic cyclic depsipeptides that are also studied for their toxicity to cancer cells. They are produced by various fungi and a direct relationship has been established between Destruxin production and the virulence of the entomopathogen Metarhizium anisopliae. Aside from opening calcium channels, their in vivo mode of action during pathogenesis remains largely uncharacterized. To better understand the effects of a destruxin, we looked at changes in gene expression following injection of Destruxin A into the fruit fly Drosophila melanogaster. Microarray results revealed reduced expression of various antimicrobial peptides (AMPs) that play a major role in the fly’s humoral immune response. Flies co-injected with a non-lethal dose of Destruxin A and the normally innocuous Gram-negative bacteria Escherichia coli, showed increased mortality and an accompanying increase in bacterial titers. Mortality due to sepsis was rescued through ectopic activation of components in the IMD pathway, one of two signal transduction pathways that are responsible for AMP induction. These results demonstrate a novel role for Destruxin A in specific suppression of the humoral immune response in insects. Keywords: Gene Expression

2007-02-10 | GSE5767 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data