scholarly journals Tobramycin suppresses cystic fibrosis lung inflammation by increasing 5′ tRNA-fMet halves secreted by P. aeruginosa

2021 ◽  
Author(s):  
Zhongyou Li ◽  
Katja Koeppen ◽  
Alix Ashare ◽  
Deborah A. Hogan ◽  
Scott A. Gerber ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Lung Function ◽  
Membrane Vesicles ◽  
Lavage Fluid ◽  
Outer Membrane Vesicles ◽  
Lung Damage ◽  
Bronchial Epithelial ◽  
Transcriptional Regulatory Mechanism ◽  
Transcriptional Regulatory ◽  
Mouse Lungs

AbstractAlthough inhaled tobramycin increases lung function in people with cystic fibrosis (pwCF), the density of P. aeruginosa in the lungs is only modestly reduced; hence, the mechanism whereby tobramycin improves lung function remains unclear. Previously, we demonstrated that P. aeruginosa secretes outer membrane vesicles (OMVs) that fuse with bronchial epithelial cells (HBECs), delivering small RNAs (sRNAs) that suppress the host immune response. Thus, we hypothesized that tobramycin modifies the sRNA content of OMVs leading to reduced inflammation and neutrophil-mediated lung damage. We found that tobramycin increased the amount of two 5′ tRNA-fMet halves in OMVs (Tobi-OMVs) and that Tobi-OMVs elicited less IL-8 secretion by CF-HBECs than control OMVs (ctrl-OMVs). A specific 5′ tRNA-fMet halves inhibitor reduced the ability of Tobi-OMVs to suppress IL-8 secretion. Tobi-OMVs were also less effective in stimulating KC secretion and neutrophil recruitment in mouse lungs compared to ctrl-OMVs. Tobramycin also reduced IL-8 and neutrophil abundance in bronchoalveolar lavage fluid obtained from pwCF. The 5′ tRNA-fMet halves reduced IL-8 secretion by an AGO2-mediated post-transcriptional regulatory mechanism. The clinical benefit of tobramycin is partly due to an increase in the secretion of 5′ tRNA-fMet halves in OMVs, leading to the attenuation of IL-8 and neutrophil-mediated CF lung damage.

scholarly journals Pseudomonas aeruginosa sabotages the generation of host proresolving lipid mediators

2016 ◽  
Vol 114 (1) ◽  
pp. 136-141 ◽  
Author(s):  
Becca A. Flitter ◽  
Kelli L. Hvorecny ◽  
Emiko Ono ◽  
Taylor Eddens ◽  
Jun Yang ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Lung Function ◽  
Epoxide Hydrolase ◽  
Pulmonary Inflammation ◽  
Critical Role ◽  
Lavage Fluid ◽  
Lipid Mediator ◽  
Epoxyeicosatrienoic Acid

Recurrent Pseudomonas aeruginosa infections coupled with robust, damaging neutrophilic inflammation characterize the chronic lung disease cystic fibrosis (CF). The proresolving lipid mediator, 15-epi lipoxin A4 (15-epi LXA4), plays a critical role in limiting neutrophil activation and tissue inflammation, thus promoting the return to tissue homeostasis. Here, we show that a secreted P. aeruginosa epoxide hydrolase, cystic fibrosis transmembrane conductance regulator inhibitory factor (Cif), can disrupt 15-epi LXA4 transcellular biosynthesis and function. In the airway, 15-epi LXA4 production is stimulated by the epithelial-derived eicosanoid 14,15-epoxyeicosatrienoic acid (14,15-EET). Cif sabotages the production of 15-epi LXA4 by rapidly hydrolyzing 14,15-EET into its cognate diol, eliminating a proresolving signal that potently suppresses IL-8–driven neutrophil transepithelial migration in vitro. Retrospective analyses of samples from patients with CF supported the translational relevance of these preclinical findings. Elevated levels of Cif in bronchoalveolar lavage fluid were correlated with lower levels of 15-epi LXA4, increased IL-8 concentrations, and impaired lung function. Together, these findings provide structural, biochemical, and immunological evidence that the bacterial epoxide hydrolase Cif disrupts resolution pathways during bacterial lung infections. The data also suggest that Cif contributes to sustained pulmonary inflammation and associated loss of lung function in patients with CF.

scholarly journals A bacterial extracellular vesicle-based intranasal vaccine against SARS-CoV-2

2021 ◽  
Author(s):  
Linglei Jiang ◽  
Tom Driedonks ◽  
Maggie Lowman ◽  
Wouter SP Jong ◽  
H. Bart van den Berg van Saparoea ◽  
...  
Keyword(s):  
Mammalian Cell Culture ◽  
Membrane Vesicles ◽  
Lavage Fluid ◽  
Extracellular Vesicle ◽  
Outer Membrane Vesicles ◽  
Lung Pathology ◽  
Live Virus ◽  
Protein Subunits ◽  
Intranasal Vaccine ◽  
And Storage

Several vaccines have been introduced to combat the coronavirus infectious disease-2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current SARS-CoV-2 vaccines include mRNA-containing lipid nanoparticles or adenoviral vectors that encode the SARS-CoV-2 Spike (S) protein of SARS-CoV-2, inactivated virus, or protein subunits. Despite growing success in worldwide vaccination efforts, additional capabilities may be needed in the future to address issues such as stability and storage requirements, need for vaccine boosters, and emergence of SARS-CoV-2 variants or entirely new viruses. Here, we present a novel, well-characterized SARS-CoV-2 vaccine candidate based on extracellular vesicles (EVs) of Salmonella typhimurium that are decorated with the mammalian cell culture-derived Spike receptor-binding domain (RBD). RBD-conjugated outer membrane vesicles (RBD-OMVs) were used to immunize the golden hamster (Mesocricetus auratus) model of COVID-19. Intranasal immunization resulted in high titers of blood anti-RBD IgG as well as detectable mucosal responses. Upon challenge with live virus, hamsters immunized with RBD-OMV, but not animals immunized with unconjugated OMVs or a vehicle control, avoided weight loss, had lower virus titers in bronchoalveolar lavage fluid, and experienced less severe lung pathology. Our results emphasize the value and versatility of OMV-based vaccine approaches.

scholarly journals Immunogenicity of Intranasally Administered Meningococcal Native Outer Membrane Vesicles in Mice

1999 ◽  
Vol 67 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Nancy B. Saunders ◽  
David R. Shoemaker ◽  
Brenda L. Brandt ◽  
E. Ellen Moran ◽  
Thomas Larsen ◽  
...  
Keyword(s):  
Immune Response ◽  
Antibody Response ◽  
Outer Membrane ◽  
Membrane Vesicles ◽  
Lavage Fluid ◽  
Lung Lavage ◽  
Outer Membrane Vesicles ◽  
Enzyme Linked Immunosorbent Assay ◽  
Natural Immunity ◽  
Bactericidal Antibody

ABSTRACT Colonization of the human nasopharyngeal region by Neisseria meningitidis is believed to lead to natural immunity. Although the presence of bactericidal antibody in serum has been correlated with immunity to meningococcal disease, mucosal immunity at the portal of entry may also play an important role. This study was undertaken to examine in mice the possibility of safely using native outer membrane vesicles (NOMV) not exposed to detergent as an intranasal (i.n.) vaccine. The mucosal and systemic responses of mice to intranasal and intraperitoneal (i.p.) vaccination with NOMV were compared over a range of doses from 0.1 to 20 μg. Intranasal vaccination of mice with NOMV induced a strong systemic bactericidal antibody response, as well as a strong local immunoglobulin A immune response in the lung as determined by assay of lung lavage fluid by enzyme-linked immunosorbent assay and lung antibody secreting cells by enzyme-linked immunospot assay. However, 8- to 10-fold-higher doses of NOMV were required i.n. compared to i.p. to elicit an equivalent bactericidal antibody response in serum. Some NOMV vaccine was aspirated into the lungs of mice during i.n. immunization and resulted in an acute inflammatory response that peaked at 1 to 2 days postimmunization and was cleared by day 7. These results indicate that i.n. delivery of meningococcal NOMV in mice is highly effective in eliciting the production of both a mucosal immune response and a systemic bactericidal antibody response.

scholarly journals Sex Steroids Induce Membrane Stress Responses and Virulence Properties in Pseudomonas aeruginosa

mBio ◽  
2020 ◽  
Vol 11 (5) ◽  
Author(s):  
Celine Vidaillac ◽  
Valerie Fei Lee Yong ◽  
Marie-Stephanie Aschtgen ◽  
Jing Qu ◽  
Shuowei Yang ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Outer Membrane ◽  
Stress Responses ◽  
Sex Steroids ◽  
Respiratory Diseases ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Membrane Stress ◽  
Content Type

ABSTRACT Estrogen, a major female sex steroid hormone, has been shown to promote the selection of mucoid Pseudomonas aeruginosa in the airways of patients with chronic respiratory diseases, including cystic fibrosis. This results in long-term persistence, poorer clinical outcomes, and limited therapeutic options. In this study, we demonstrate that at physiological concentrations, sex steroids, including testosterone and estriol, induce membrane stress responses in P. aeruginosa. This is characterized by increased virulence and consequent inflammation and release of proinflammatory outer membrane vesicles promoting in vivo persistence of the bacteria. The steroid-induced P. aeruginosa response correlates with the molecular polarity of the hormones and membrane fluidic properties of the bacteria. This novel mechanism of interaction between sex steroids and P. aeruginosa explicates the reported increased disease severity observed in females with cystic fibrosis and provides evidence for the therapeutic potential of the modulation of sex steroids to achieve better clinical outcomes in patients with hormone-responsive strains. IMPORTANCE Molecular mechanisms by which sex steroids interact with P. aeruginosa to modulate its virulence have yet to be reported. Our work provides the first characterization of a steroid-induced membrane stress mechanism promoting P. aeruginosa virulence, which includes the release of proinflammatory outer membrane vesicles, resulting in inflammation, host tissue damage, and reduced bacterial clearance. We further demonstrate that at nanomolar (physiological) concentrations, male and female sex steroids promote virulence in clinical strains of P. aeruginosa based on their dynamic membrane fluidic properties. This work provides, for the first-time, mechanistic insight to better understand and predict the P. aeruginosa related response to sex steroids and explain the interindividual patient variability observed in respiratory diseases such as cystic fibrosis that are complicated by gender differences and chronic P. aeruginosa infection.

scholarly journals Pseudomonas aeruginosa leucine aminopeptidase influences early biofilm composition and structure via vesicle-associated anti-biofilm activity

2019 ◽  
Author(s):  
Caitlin N. Esoda ◽  
Meta J. Kuehn
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Outer Membrane ◽  
Biofilm Formation ◽  
Leucine Aminopeptidase ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Bacterial Biofilm ◽  
Biofilm Architecture ◽  
Biofilm Development

AbstractPseudomonas aeruginosa, known as one of the leading causes of disease in cystic fibrosis (CF) patients, secretes a variety of proteases. These enzymes contribute significantly to P. aeruginosa pathogenesis and biofilm formation in the chronic colonization of CF patient lungs, as well as playing a role in infections of the cornea, burn wounds and chronic wounds. We previously characterized a secreted P. aeruginosa peptidase, PaAP, that is highly expressed in chronic CF isolates. This leucine aminopeptidase is highly expressed during infection and in biofilms, and it associates with bacterial outer membrane vesicles (OMVs), structures known to contribute to virulence mechanisms in a variety of Gram-negative species and one of the major components of the biofilm matrix. We hypothesized that PaAP may play a role in P. aeruginosa biofilm formation. Using a lung epithelial cell/bacterial biofilm coculture model, we show that PaAP deletion in a clinical P. aeruginosa background alters biofilm microcolony composition to increase cellular density, while decreasing matrix polysaccharide content, and that OMVs from PaAP expressing strains but not PaAP alone or in combination with PaAP deletion strain-derived OMVs could complement this phenotype. We additionally found that OMVs from PaAP expressing strains could cause protease-mediated biofilm detachment, leading to changes in matrix and colony composition. Finally, we showed that the OMVs could also mediate the detachment of biofilms formed by both non-self P. aeruginosa strains and Klebsiella pneumoniae, another respiratory pathogen. Our findings represent novel roles for OMVs and the aminopeptidase in the modulation of P. aeruginosa biofilm architecture.ImportanceBiofilm formation by the bacterial pathogen P. aeruginosa is known to contribute to drug- resistance in nosocomial infections and chronic lung infections of cystic fibrosis patients. In order to treat these infections more successfully, the mechanisms of bacterial biofilm development must be elucidated. While both bacterially-secreted aminopeptidase and outer membrane vesicles have been shown to be abundant in P. aeruginosa biofilm matrices, the contributions of each of these factors to the steps in biofilm generation have not been well studied. This work provides new insight as to how these bacterial components mediate the formation of a robust, drug-resistant extracellular matrix and implicates outer membrane vesicles as active components of biofilm architecture, expanding our overall understanding of P. aeruginosa biofilm biology.

scholarly journals Structural determinants of long-term functional outcomes in young children with cystic fibrosis

2020 ◽  
Vol 55 (5) ◽  
pp. 1900748 ◽  
Author(s):  
Lidija Turkovic ◽  
Daan Caudri ◽  
Tim Rosenow ◽  
Oded Breuer ◽  
Conor Murray ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Lung Function ◽  
Lung Disease ◽  
Chest Ct ◽  
Lung Damage ◽  
Wall Thickening ◽  
Lung Function Decline ◽  
Children's Hospital ◽  
Children’S Hospital

BackgroundAccelerated lung function decline in individuals with cystic fibrosis (CF) starts in adolescence with respiratory complications being the most common cause of death in later life. Factors contributing to lung function decline are not well understood, in particular its relationship with structural lung disease in early childhood. Detection and management of structural lung disease could be an important step in improving outcomes in CF patients.MethodsAnnual chest computed tomography (CT) scans were available from 2005 to 2016 as a part of the AREST CF cohort for children aged 3 months to 6 years. Annual spirometry measurements were available for 89.77% of the cohort (167 children aged 5–6 years) from age 5 to 15 years through outpatient clinics at Perth Children's Hospital (Perth, Australia) and The Royal Children's Hospital in Melbourne (Melbourne, Australia) (697 measurements, mean±sd age 9.3±2.1 years).ResultsChildren with a total CT score above the median at age 5–6 years were more likely to have abnormal forced expiratory volume in 1 s (FEV1) (adjusted hazard ratio 2.67 (1.06–6.72), p=0.037) during the next 10 years compared to those below the median chest CT score. The extent of all structural abnormalities except bronchial wall thickening were associated with lower FEV1 Z-scores. Mucus plugging and trapped air were the most predictive sub-score (adjusted mean change −0.17 (−0.26 – −0.07) p<0.001 and −0.09 (−0.14 – −0.04) p<0.001, respectively).DiscussionChest CT identifies children at an early age who have adverse long-term outcomes. The prevention of structural lung damage should be a goal of early intervention and can be usefully assessed with chest CT. In an era of therapeutics that might alter disease trajectories, chest CT could provide an early readout of likely long-term success.

scholarly journals Proteomic Studies of the Biofilm Matrix including Outer Membrane Vesicles of Burkholderia multivorans C1576, a Strain of Clinical Importance for Cystic Fibrosis

2020 ◽  
Vol 8 (11) ◽  
pp. 1826
Author(s):  
Lucrecia C. Terán ◽  
Marco Distefano ◽  
Barbara Bellich ◽  
Sara Petrosino ◽  
Paolo Bertoncin ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Outer Membrane ◽  
Outer Membrane Proteins ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Ros Scavenging ◽  
Burkholderia Multivorans ◽  
Proteomic Approach ◽  
The Matrix ◽  
Biofilm Matrix

Biofilms are aggregates of microbial cells encased in a highly hydrated matrix made up of self-produced extracellular polymeric substances (EPS) which consist of polysaccharides, proteins, nucleic acids, and lipids. While biofilm matrix polysaccharides are unraveled, there is still poor knowledge about the identity and function of matrix-associated proteins. With this work, we performed a comprehensive proteomic approach to disclose the identity of proteins associated with the matrix of biofilm-growing Burkholderia multivorans C1576 reference strain, a cystic fibrosis clinical isolate. Transmission electron microscopy showed that B. multivorans C1576 also releases outer membrane vesicles (OMVs) in the biofilm matrix, as already demonstrated for other Gram-negative species. The proteomic analysis revealed that cytoplasmic and membrane-bound proteins are widely represented in the matrix, while OMVs are highly enriched in outer membrane proteins and siderophores. Our data suggest that cell lysis and OMVs production are the most important sources of proteins for the B. multivorans C1576 biofilm matrix. Of note, some of the identified proteins are lytic enzymes, siderophores, and proteins involved in reactive oxygen species (ROS) scavenging. These proteins might help B. multivorans C1576 in host tissue invasion and defense towards immune system assaults.

scholarly journals Outer Membrane Vesicles Derived from Klebsiella pneumoniae Influence the miRNA Expression Profile in Human Bronchial Epithelial BEAS-2B Cells

2020 ◽  
Vol 8 (12) ◽  
pp. 1985
Author(s):  
Federica Dell’Annunziata ◽  
Concetta Paola Ilisso ◽  
Carmela Dell’Aversana ◽  
Giuseppe Greco ◽  
Alessandra Coppola ◽  
...  
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Klebsiella Pneumoniae ◽  
Outer Membrane ◽  
Expression Profile ◽  
Mirna Expression ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Human Bronchial Epithelial Cells ◽  
Bronchial Epithelial

Klebsiella pneumoniae is an opportunistic pathogen that causes nosocomial and community-acquired infections. The spread of resistant strains of K. pneumoniae represents a growing threat to human health, due to the exhaustion of effective treatments. K. pneumoniae releases outer membrane vesicles (OMVs). OMVs are a vehicle for the transport of virulence factors to host cells, causing cell injury. Previous studies have shown changes of gene expression in human bronchial epithelial cells after treatment with K. pneumoniae OMVs. These variations in gene expression could be regulated through microRNAs (miRNAs), which participate in several biological mechanisms. Thereafter, miRNA expression profiles in human bronchial epithelial cells were evaluated during infection with standard and clinical K. pneumoniae strains. Microarray analysis and RT-qPCR identified the dysregulation of miR-223, hsa-miR-21, hsa-miR-25 and hsa-let-7g miRNA sequences. Target gene prediction revealed the essential role of these miRNAs in the regulation of host immune responses involving NF-ĸB (miR-223), TLR4 (hsa-miR-21), cytokine (hsa-miR-25) and IL-6 (hsa-let-7g miRNA) signalling pathways. The current study provides the first large scale expression profile of miRNAs from lung cells and predicted gene targets, following exposure to K. pneumoniae OMVs. Our results suggest the importance of OMVs in the inflammatory response.

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