scholarly journals Characterization of Outer Membrane Vesicles fromBrucella melitensisand Protection Induced in Mice

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Eric Daniel Avila-Calderón ◽  
Ahidé Lopez-Merino ◽  
Neeta Jain ◽  
Humberto Peralta ◽  
Edgar Oliver López-Villegas ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Virulent Strain ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Saline Control ◽  
Control Group ◽  
Cell Mediated Immunity ◽  
Rough Strain ◽  
Smooth Strain

The outer membrane vesicles (OMVs) from smoothB. melitensis16 M and a derived rough mutant, VTRM1 strain, were purified and characterized with respect to protein content and induction of immune responses in mice. Proteomic analysis showed 29 proteins present in OMVs fromB. melitensis16 M; some of them are well-knownBrucellaimmunogens such as SOD, GroES, Omp31, Omp25, Omp19, bp26, and Omp16. OMVs from a rough VTRM1 induced significantly higher expression of IL-12, TNFα, and IFNγ genes in bone marrow dendritic cells than OMVs from smooth strain 16 M. Relative to saline control group, mice immunized intramuscularly with rough and smooth OMVs were protected from challenge with virulent strainB. melitensis16 M just as well as the group immunized with live strainB. melitensisRev1 (P<0.005). Additionally, the levels of serum IgG2a increased in mice vaccinated with OMVs from rough strain VTRM1 consistent with the induction of cell-mediated immunity.

Electrophysiological Characterization of Transport Across Outer Membrane Channels from Gram-Negative Bacteria in Their Native Environment

2019 ◽  
Author(s):  
Jiajun Wang ◽  
Rémi Terrasse ◽  
Jayesh Arun Bafna ◽  
Lorraine Benier ◽  
Mathias Winterhalter
Keyword(s):  
Outer Membrane ◽  
Lipid Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Multi Drug Resistance ◽  
Gram Negative Bacteria ◽  
Membrane Channels ◽  
Gram Negative ◽  
Electrophysiological Characterization

Multi-drug resistance in Gram-negative bacteria is often associated with low permeability of the outer membrane. To investigate the role of membrane channels in the uptake of antibiotics, we extract, purify and reconstitute them into artificial planar membranes. To avoid this time-consuming procedure, here we show a robust approach using fusion of native outer membrane vesicles (OMV) into planar lipid bilayer which moreover allows also to some extend the characterization of membrane protein channels in their native environment. Two major membrane channels from <i>Escherichia coli</i>, OmpF and OmpC, were overexpressed from the host and the corresponding OMVs were collected. Each OMV fusion revealed surprisingly single or only few channel activities. The asymmetry of the OMV´s translates after fusion into the lipid membrane with the LPS dominantly present at the side of OMV addition. Compared to conventional reconstitution methods, the channels fused from OMVs containing LPS have similar conductance but a much broader distribution. The addition of Enrofloxacin on the LPS side yields somewhat higher association (<i>k<sub>on</sub></i>) and lower dissociation (<i>k<sub>off</sub></i>) rates compared to LPS-free reconstitution. We conclude that using outer membrane vesicles is a fast and easy approach for functional and structural studies of membrane channels in the native membrane.

Characterization of outer membrane vesicles of Acetobacter pasteurianus NBRC3283

2018 ◽  
Vol 125 (4) ◽  
pp. 425-431 ◽  
Author(s):  
Masahito Hashimoto ◽  
Taichi Matsumoto ◽  
Miwa Tamura-Nakano ◽  
Mami Ozono ◽  
Shuhei Hashiguchi ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Acetobacter Pasteurianus

scholarly journals Identification and characterization of the α-CA in the outer membrane vesicles produced by Helicobacter pylori

2019 ◽  
Vol 34 (1) ◽  
pp. 189-195 ◽  
Author(s):  
Maurizio Ronci ◽  
Sonia Del Prete ◽  
Valentina Puca ◽  
Simone Carradori ◽  
Vincenzo Carginale ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Outer Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Identification And Characterization

Acellular outer membrane vesicles of Brucella abortus strain 19 elicits both humoral and cell mediated immune response in mice

2018 ◽  
Author(s):  
Losa Rose ◽  
Bablu Kumar ◽  
Ankita Jain ◽  
M K Singh ◽  
Abhishek .
Keyword(s):  
Immune Response ◽  
Outer Membrane ◽  
Brucella Abortus ◽  
Outer Membrane Proteins ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Biologically Active ◽  
Cell Mediated Immunity ◽  
Humoral Immune ◽  
Sds Page

Outer membrane vesicles (OMVs) contain biologically active proteins, lipoolysaccharide (LPS), periplasmic and membrane-bound proteins and are known to perform diverse biological functions. OMVs from Brucella abortus S19 were isolated and characterized by transmission electron microscopy (TEM), SDS-PAGE and immunoreactivity was investigated by western blotting. On TEM, bilayered spherical structures of 50-200 nm were observed. SDS-PAGE of OMVs revealed approximate bands size of 82 kDa, 68 kDa, 38 kDa, 32 kDa, 29 kDa and 18 kDa. Western blot analysis of OMVs revealed a dominant immunoreactive band of 38 kDa that correspond to some major outer membrane proteins. Humoral immune response was measured by indirect ELISA which showed that OMV specific antibodies were detected from 7th day post immunization (DPI) onwards and showed a rising trend up to 35th DPI. Cell mediated immune (CMI) response against OMVs as evidenced by the proliferation of splenocytes have also been observed. Thus OMVs were found to possess immunogenic proteins which had potential to induce both humoral as well as cell mediated immunity. After correlating this immune response with protection it has been concluded that OMV can be used as one of the vaccine candidate against brucellosis.

scholarly journals Immune responses of meningococcal B outer membrane vesicles in middle-aged mice

2020 ◽  
Vol 78 (5) ◽  
Author(s):  
Gabriela Trzewikoswki de Lima ◽  
Thais Sousa Rodrigues ◽  
Amanda Izeli Portilho ◽  
Victor Araujo Correa ◽  
Emanuelle Baldo Gaspar ◽  
...  
Keyword(s):  
Immune Response ◽  
Outer Membrane ◽  
Membrane Vesicles ◽  
The Elderly ◽  
Outer Membrane Vesicles ◽  
Control Group ◽  
Middle Aged ◽  
Aged Mice ◽  
Robust Immune Response

ABSTRACT The elderly are more likely to die when infected with Neisseria meningitidis. Aging is associated with immune system dysfunctions that impair responses to vaccines and infections. Therefore, immunization of middle-aged individuals could be beneficial. This study aims to evaluate the immunogenicity of N. meningitidis B outer membrane vesicles (OMVs) complexed to two different adjuvants. Middle-aged BALB/c and A/Sn mice were immunized and subsequent immune response was assessed by ELISA, immunoblotting and ELISpot. IgG levels were similar between the animals immunized with OMVs complexed to adjuvants. A total of 235 days after the last immunization only A/Sn mice presented higher IgG levels than those observed in the baseline, especially the group immunized with OMVs and aluminum hydroxide. The predominant IgG subclasses were IgG2a and IgG2b. Immunization with the three-dose regimen generated IgG antibodies that recognized a variety of antigens present in the homologous and heterologous meningococcal OMVs evaluated. There was an increase in the frequency of antigen-specific IFN-γ secreting splenocytes, after in vitro stimulation, in mice immunized with OMVs and adjuvants compared to the control group, almost 1 year after the last immunization. Both adjuvants showed similar performance. Immunization of middle-aged mice has generated a robust immune response and it appears to be advantageous.

Proteomic and functional characterization of the outer membrane vesicles from the gastric pathogen Helicobacter pylori

2009 ◽  
Vol 3 (7) ◽  
pp. 785-796 ◽  
Author(s):  
Erica Mullaney ◽  
Paul A. Brown ◽  
Sinead M. Smith ◽  
Catherine H. Botting ◽  
Yoshio Y. Yamaoka ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Outer Membrane ◽  
Functional Characterization ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Gastric Pathogen
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