scholarly journals Isolation and immunogenicity of extracted outer membrane vesicles from Pseudomonas aeruginosa under antibiotics treatment conditions

2021 ◽  
Author(s):  
Mehdi Hadadi-Fishani ◽  
Shahin Najar-Peerayeh ◽  
Seyed Davar Siadat ◽  
Mohammad Sekhavati ◽  
Ashraf Mohabati Mobarez
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bactericidal Activity ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Serum Bactericidal Activity ◽  
Treatment Conditions ◽  
Physicochemical Features ◽  
Igg1 Subclass ◽  
And Function ◽  
Cellular Immune

Background and Objectives: Different types of antibiotics have been indicated to enhance the secretion of OMVs from Pseudomonas aeruginosa. We aimed to investigate the effect of meropenem and amikacin antibiotics on inducing the secre- tion of OMVs and immunologic features in P. aeruginosa. Materials and Methods: The OMVs were prepared from P. aeruginosa under hypervesiculation condition (treatment with amikacin and meropenem), and extraction was carried out by the sequential ultracentrifugation. Physicochemical features of extracted OMVs were evaluated by electron microscopy and SDS-PAGE. To quantify antibody synthesis and function after immunization with OMV, we used ELISA, serum bactericidal activity, and opsonophagocytosis. Production of cytokines from splenocytes of immunized mice was measured with ELISA. Results: Specific-antibody IgG production, particularly IgG1 subclass, increased in mice primed with hypervesiculation-de- rived OMVs compared to normal condition-derived OMVs. Serum bactericidal activity and opsonophagocytosis of secreted antibody was enhanced in mice primed with hypervesiculation-derived OMVs. Investigation of cytokine production showed the upregulation of IL-8, IL-12, IL-17, and TNF-α and downregulation of IL-10. Conclusion: Based on our findings, OMVs production can be increased by treating P. aeruginosa with amikacin and mero- penem antibiotics. Moreover, hypervesiculation-derived OMV scan possibly activate the humoral and cellular immune re- sponse more than normal OMVs.

scholarly journals Relative Immunogenicity of PorA Subtypes in a Multivalent Neisseria meningitidis Vaccine Is Not Dependent on Presentation Form

2003 ◽  
Vol 71 (11) ◽  
pp. 6367-6371 ◽  
Author(s):  
Thomas A. Luijkx ◽  
Harry van Dijken ◽  
Hendrik-Jan Hamstra ◽  
Betsy Kuipers ◽  
Peter van der Ley ◽  
...  
Keyword(s):  
Neisseria Meningitidis ◽  
Outer Membrane ◽  
Bactericidal Activity ◽  
Immunoglobulin G ◽  
Clinical Studies ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
The Other ◽  
Meningococcal Vaccine ◽  
Serum Bactericidal Activity

ABSTRACT The hexavalent meningococcal vaccine HexaMen, containing six PorAs on two vesicles, was tested in clinical studies. Although fourfold increases in serum bactericidal activity (SBA) titers against all of the PorAs were observed, there were significant differences between PorA-specific SBA titers. SBA titers were mainly directed against one PorA from each vesicle, P1.5-2,10 and P1.5-1,2-2, and were lower against the other PorAs, especially P1.7-2,4 and P1.19,15-1. We investigated whether these differences were due to immunological interference that resulted in competition between the three PorAs on the same vesicle or whether they were caused by a difference in the immunogenicities of the separate PorAs. Therefore, mice were immunized either with HexaMen, with six monovalent outer membrane vesicles (OMVs) representing the same six PorAs simultaneously (HexaMix), or with only one of the monovalent OMVs. The immunoglobulin G and SBA titers after HexaMen immunization in mice resembled the results obtained in clinical studies. Although immunization with HexaMix gave higher titers than immunization with HexaMen for some PorAs, the pattern of high and low titers was the same. Similar differences in immunogenicity between subtypes were seen after monovalent immunization when interference was eliminated as a cause of the differences. Monovalent immunization resulted in higher titers for P1.5-1,2-2 and P1.7,16 than immunization with HexaMen. However, no significant differences were found for the weakly immunogenic PorAs, P1.7-2,4 and P1.19,15-1. Since immunization with the six PorAs in the trivalent presentation form (HexaMen) and in the mixture of monovalent vesicles (HexaMix) resulted in the same pattern of high and low titers, we concluded that the differences between the PorA-specific responses are due to differences in the immunogenicities of the various PorAs and not due to interference that results in competition between different PorAs.

Recombinant Pseudomonas bio-nanoparticles induce protection against pneumonic Pseudomonas aeruginosa infection

2021 ◽  
Author(s):  
Peng Li ◽  
Xiuran Wang ◽  
Xiangwan Sun ◽  
Jesse Cimino ◽  
Ziqiang Guan ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Fusion Gene ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Wild Type ◽  
Generation Vaccine ◽  
Pseudomonas Aeruginosa Infection ◽  
Reduced Toxicity ◽  
Opsonophagocytic Killing ◽  
High Immunogenicity

To develop an effective Pseudomonas aeruginosa (PA) outer-membrane-vesicles (OMVs) vaccine, we eliminated multiple virulence factors from a wild-type P. aeruginosa PA103 strain (PA103) to generate a recombinant strain, PA-m14. The PA-m14 strain was tailored with a pSMV83 plasmid encoding the pcrV-hitA T fusion gene to produce OMVs. The recombinant OMVs enclosed increased amounts of PcrV-HitA T bivalent antigen (PH) (termed OMV-PH) and exhibited reduced toxicity compared to the OMVs from PA103. Intramuscular vaccination with OMV-PH from PA-m14(pSMV83) afforded 70% protection against intranasal challenge with 6.5 × 10 6 CFU (∼30 LD 50 ) of PA103, while immunization using OMVs without the PH antigen (termed OMV-NA) or the PH antigen alone failed to offer effective protection against the same challenge. Further immune analysis showed that the OMV-PH immunization significantly stimulated potent antigen-specific humoral and T-cell (Th1/Th17) responses in comparison to the PH or OMV-NA immunization in mice, which can effectively hinder PA infection. Undiluted anti-sera from OMV-PH-immunized mice displayed significant opsonophagocytic killing of WT PA103 compared to antisera from PH antigen- or OMV-NA-immunized mice. Moreover, the OMV-PH immunization afforded significant antibody-indentpednet cross-protection to mice against PAO1 and a clinical isolate AMC-PA10 strains. Collectively, the recombinant PA OMV delivering the PH bivalent antigen exhibits high immunogenicity and would be a promising next-generation vaccine candidate against PA infection.

scholarly journals Cyclodextrins reduce the ability of Pseudomonas aeruginosa outer-membrane vesicles to reduce CFTR Cl− secretion

2019 ◽  
Vol 316 (1) ◽  
pp. L206-L215 ◽  
Author(s):  
Roxanna Barnaby ◽  
Katja Koeppen ◽  
Bruce A. Stanton
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Epithelial Cells ◽  
Outer Membrane ◽  
Membrane Vesicles ◽  
Airway Epithelial Cells ◽  
Outer Membrane Vesicles ◽  
Airway Epithelial ◽  
Ussing Chambers ◽  
Planktonic Growth ◽  
Apical Side

Pseudomonas aeruginosa secretes outer-membrane vesicles (OMVs) that fuse with cholesterol-rich lipid rafts in the apical membrane of airway epithelial cells and decrease wt-CFTR Cl− secretion. Herein, we tested the hypothesis that a reduction of the cholesterol content of CF human airway epithelial cells by cyclodextrins reduces the inhibitory effect of OMVs on VX-809 (lumacaftor)-stimulated Phe508del CFTR Cl− secretion. Primary CF bronchial epithelial cells and CFBE cells were treated with vehicle, hydroxypropyl-β-cyclodextrin (HPβCD), or methyl-β-cyclodextrin (MβCD), and the effects of OMVs secreted by P. aeruginosa on VX-809 stimulated Phe508del CFTR Cl− secretion were measured in Ussing chambers. Neither HPβCD nor MβCD were cytotoxic, and neither altered Phe508del CFTR Cl− secretion. Both cyclodextrins reduced OMV inhibition of VX-809-stimulated Phe508del-CFTR Cl− secretion when added to the apical side of CF monolayers. Both cyclodextrins also reduced the ability of P. aeruginosa to form biofilms and suppressed planktonic growth of P. aeruginosa. Our data suggest that HPβCD, which is in clinical trials for Niemann-Pick Type C disease, and MβCD, which has been approved by the U.S. Food and Drug Administration for use in solubilizing lipophilic drugs, may enhance the clinical efficacy of VX-809 in CF patients when added to the apical side of airway epithelial cells, and reduce planktonic growth and biofilm formation by P. aeruginosa. Both effects would be beneficial to CF patients.

scholarly journals Structural Changes and Differentially Expressed Genes in Pseudomonas aeruginosa Exposed to Meropenem-Ciprofloxacin Combination

2014 ◽  
Vol 58 (7) ◽  
pp. 3957-3967 ◽  
Author(s):  
Vera Lúcia Dias Siqueira ◽  
Rosilene Fressatti Cardoso ◽  
Katiany Rizzieri Caleffi-Ferracioli ◽  
Regiane Bertin de Lima Scodro ◽  
Maria Aparecida Fernandez ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Structural Changes ◽  
Membrane Vesicles ◽  
Sos Response ◽  
Outer Membrane Vesicles ◽  
Synergistic Action ◽  
Differentially Expressed ◽  
Representational Difference Analysis ◽  
Content Type ◽  
Time Kill

ABSTRACTThe effect of a meropenem-ciprofloxacin combination (MCC) on the susceptibility of multidrug-resistant (MDR)Pseudomonas aeruginosa(MRPA) clinical isolates was determined using checkerboard and time-kill curve techniques. Structural changes and differential gene expression that resulted from the synergistic action of the MCC against one of theP. aeruginosaisolates (1071-MRPA]) were evaluated using electron microscopy and representational difference analysis (RDA), respectively. The differentially expressed, SOS response-associated, and resistance-associated genes in 1071-MRPA exposed to meropenem, ciprofloxacin, and the MCC were monitored by quantitative PCR. The MCC was synergistic against 25% and 40.6% of MDRP. aeruginosaisolates as shown by the checkerboard and time-kill curves, respectively. The morphological and structural changes that resulted from the synergistic action of the MCC against 1071-MRPA were a summation of the effects observed with each antimicrobial alone. One exception included outer membrane vesicles, which were seen in a greater amount upon ciprofloxacin exposure but were significantly inhibited upon MCC exposure. Cell wall- and DNA repair-associated genes were differentially expressed in 1071-MRPA exposed to meropenem, ciprofloxacin, and the MCC. However, some of the RDA-detected, resistance-associated, and SOS response-associated genes were expressed at significantly lower levels in 1071-MRPA exposed to the MCC. The MCC may be an alternative for the treatment of MDRP. aeruginosa. The effect of this antimicrobial combination may be not only the result of a summation of the effects of meropenem and ciprofloxacin but also a result of differential action that likely inhibits protective mechanisms in the bacteria.

scholarly journals Distinct Susceptibilities of Corneal Pseudomonas aeruginosa Clinical Isolates to Neutrophil Extracellular Trap-Mediated Immunity

2014 ◽  
Vol 82 (10) ◽  
pp. 4135-4143 ◽  
Author(s):  
Qiang Shan ◽  
Markryan Dwyer ◽  
Samir Rahman ◽  
Mihaela Gadjeva
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Serine Proteases ◽  
Membrane Vesicles ◽  
Nuclease Activity ◽  
Outer Membrane Vesicles ◽  
Clinical Isolates ◽  
Neutrophil Extracellular Trap ◽  
Ocular Infection ◽  
Content Type

ABSTRACTOcular bacterial keratitis, often associated withPseudomonas aeruginosabacterial infection, commonly occurs in contact lens wearers and may lead to vision impairment. In this study, we analyzed the contribution of neutrophil extracellular traps (NETs) to the mediation of protection during ocular keratitis. Both invasive and cytotoxicP. aeruginosaclinical isolates induced NET release by neutrophils. NETs carried the characteristic histone proteins, elastase, lysozyme, myeloperoxidase, and metabolic enzymes. While the invasiveP. aeruginosastrains PAO1 (serogroup O5) and 6294 (serogroup O6) were trapped by NETs, the cytotoxicP. aeruginosastrains 6077, 6206 (serogroup O11), and PA14 (serogroup 010) were less sensitive to NET capture. The mechanism of escape by the cytotoxic strains from adhesion to NETs involved the shedding of outer membrane vesicles (OMVs) that outcompeted the cytotoxicP. aeruginosastrains for NET binding. When ocular infection was caused by an invasive strainin vivo, NETs were released at the ocular surface to capture bacteria, limiting their spread. Treatment with MNase I had a dose-dependent effect, with low doses of MNase speeding up bacterial clearance and high doses of MNase having toxic consequences. Cumulatively, our data suggest that NET-mediated immunity is a two-step process. Initially, pathogens attach to NET fragments; subsequently, upon nuclease activity, active serine proteases, which proteolytically degrade NET-associated proteins and promote DNase activity, are released. Therefore, a balance between NET production and NET degradation is needed to achieve maximal NET immunity.

scholarly journals Intra- and Interspecies Effects of Outer Membrane Vesicles from Stenotrophomonas maltophilia on β-Lactam Resistance

2016 ◽  
Vol 60 (4) ◽  
pp. 2516-2518 ◽  
Author(s):  
Simon Devos ◽  
Stephan Stremersch ◽  
Koen Raemdonck ◽  
Kevin Braeckmans ◽  
Bart Devreese
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Outer Membrane ◽  
Stenotrophomonas Maltophilia ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Burkholderia Cenocepacia ◽  
Content Type

ABSTRACTThe treatment ofStenotrophomonas maltophiliainfection with β-lactam antibiotics leads to increased release of outer membrane vesicles (OMVs), which are packed with two chromosomally encoded β-lactamases. Here, we show that these β-lactamase–packed OMVs are capable of establishing extracellular β-lactam degradation. We also show that they dramatically increase the apparent MICs of imipenem and ticarcillin for the cohabituating speciesPseudomonas aeruginosaandBurkholderia cenocepacia.

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