scholarly journals Outer Membrane Vesicles From Probiotic and Commensal Escherichia coli Activate NOD1-Mediated Immune Responses in Intestinal Epithelial Cells

2018 ◽  
Vol 9 ◽  
Author(s):  
María-Alexandra Cañas ◽  
María-José Fábrega ◽  
Rosa Giménez ◽  
Josefa Badia ◽  
Laura Baldomà
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Immune Responses ◽  
Outer Membrane ◽  
Intestinal Epithelial Cells ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Intestinal Epithelial

scholarly journals Strong Decrease in Invasive Ability and Outer Membrane Vesicle Release in Crohn's Disease-Associated Adherent-Invasive Escherichia coli Strain LF82 with the yfgL Gene Deleted

2005 ◽  
Vol 187 (7) ◽  
pp. 2286-2296 ◽  
Author(s):  
Nathalie Rolhion ◽  
Nicolas Barnich ◽  
Laurent Claret ◽  
Arlette Darfeuille-Michaud
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Outer Membrane ◽  
Culture Supernatant ◽  
Intestinal Epithelial Cells ◽  
Outer Membrane Proteins ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Intestinal Epithelial ◽  
Isogenic Mutant

ABSTRACT Adherent-invasive Escherichia coli strain LF82 recovered from a chronic lesion of a patient with Crohn's disease is able to invade cultured intestinal epithelial cells. Three mutants with impaired ability to invade epithelial cells had the Tn5phoA transposon inserted in the yfgL gene encoding the YfgL lipoprotein. A yfgL- negative isogenic mutant showed a marked decrease both in its ability to invade Intestine-407 cells and in the amount of the outer membrane proteins OmpA and OmpC in the culture supernatant, as shown by analysis of the culture supernatant protein contents by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization-time of flight mass spectrometry. Transcomplementation of the LF82-ΔyfgL isogenic mutant with the cloned yfgL gene restored invasion ability and outer membrane protein release in the culture supernatant. The outer membrane proteins in the culture supernatant of strain LF82 resulted from the formation of vesicles. This was shown by Western blot analysis of periplasmic and outer membrane fraction markers typically found in outer membrane vesicles and by transmission electron microscopic analysis of ultracentrifuged cell-free LF82 supernatant pellets, indicating the presence of vesicles with a bilayered structure surrounding a central electron-dense core. Thus, deletion of the yfgL gene in strain LF82 resulted in a decreased ability to invade intestinal epithelial cells and a decreased release of outer membrane vesicles.

scholarly journals Exploiting bacterial outer membrane vesicles as a cross-protective vaccine candidate against avian pathogenic Escherichia coli

2020 ◽  
Author(s):  
Rujiu Hu ◽  
Jing Li ◽  
Hua Lin ◽  
Liu Liang ◽  
Yuezhen Zhao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Immune Responses ◽  
Outer Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Cross Protection ◽  
Avian Pathogenic Escherichia Coli ◽  
Vaccine Candidates ◽  
Pathogenic Escherichia Coli ◽  
Bacterial Outer Membrane

Abstract Background: The well-known fact that avian pathogenic Escherichia coli (APEC) is harder to prevent due to its numerous serogroups has promoted the development of biological immunostimulatory materials as new vaccine candidates in poultry farms. Bacterial outer membrane vesicles (OMVs), known as spherical nanovesicles enriched with various immunostimulants, are naturally secreted by Gram-negative bacteria, and have gained much attention for developing effective vaccine candidates. Here, a novel multi-serogroup OMVs (MOMVs) vaccine was developed to achieve cross-protection against APEC infection in broiler chickens.Results: In this study, OMVs produced by three APEC strains were isolated, purified and prepared into MOMVs by mixing these three OMVs. By using SDS-PAGE and LC-MS/MS, 159 proteins were identified in MOMVs and the subcellular location and biological functions of 20 most abundant proteins were analyzed. The immunogenicity of MOMVs was evaluated, and the results showed that MOMVs could elicit innate immune responses, including internalization by chicken macrophage and production of immunomodulatory cytokines. Vaccination with MOMVs induced specific broad-spectrum antibodies as well as Th1 and Th17 immune responses. The animal experiment has confirmed that immunization with an appropriate dose of MOMVs could not cause any adverse effect and was able to reduce bacteria loads and pro-inflammatory cytokines production, thus providing effective cross-protection against lethal infections induced by multi-serogroup APEC in chickens. Further experiments indicated that, although vesicular proteins were able to induce stronger protective efficiency than lipopolysaccharide, both vesicular proteins and lipopolysaccharide are crucial in MOMVs-mediated protection.Conclusions: The multi-serogroup nanovesicles produced by APEC strains will open up a new way for the development of next generation vaccines with low toxicity and broad protection in the treatment and control of APEC infection.

scholarly journals Exploiting bacterial outer membrane vesicles as a cross-protective vaccine candidate against avian pathogenic Escherichia coli (APEC)

2020 ◽  
Author(s):  
Rujiu Hu ◽  
Jing Li ◽  
Yuezhen Zhao ◽  
Hua Lin ◽  
Liu Liang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Immune Responses ◽  
Outer Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Cross Protection ◽  
Effective Vaccine ◽  
Protective Efficiency ◽  
Vaccine Candidates ◽  
Bacterial Outer Membrane

Abstract Background: The well-known fact that avian pathogenic Escherichia coli (APEC) is harder to prevent due to its numerous serogroups has promoted the development of biological immunostimulatory materials as new vaccine candidates in poultry farms. Bacterial outer membrane vesicles (OMVs), known as spherical nanovesicles enriched with various immunostimulants, are naturally secreted by Gram-negative bacteria, and have gained much attention for developing effective vaccine candidates. Recent report has demonstrated that OMVs of APEC O78 can induce protective immunity in chickens. Here, a novel multi-serogroup OMVs (MOMVs) vaccine was developed to achieve cross-protection against APEC infection in broiler chickens.Results: In this study, OMVs produced by three APEC strains were isolated, purified and prepared into MOMVs by mixing these three OMVs. By using SDS-PAGE and LC-MS/MS, 159 proteins were identified in MOMVs and the subcellular location and biological functions of 20 most abundant proteins were analyzed. The immunogenicity of MOMVs was evaluated, and the results showed that MOMVs could elicit innate immune responses, including internalization by chicken macrophage and production of immunomodulatory cytokines. Vaccination with MOMVs induced specific broad-spectrum antibodies as well as Th1 and Th17 immune responses. The animal experiment has confirmed that immunization with an appropriate dose of MOMVs could not cause any adverse effect and was able to reduce bacteria loads and pro-inflammatory cytokines production, thus providing effective cross-protection against lethal infections induced by multi-serogroup APEC strains in chickens. Further experiments indicated that, although vesicular proteins were able to induce stronger protective efficiency than lipopolysaccharide, both vesicular proteins and lipopolysaccharide are crucial in MOMVs-mediated protection. Conclusions: The multi-serogroup nanovesicles produced by APEC strains will open up a new way for the development of next generation vaccines with low toxicity and broad protection in the treatment and control of APEC infection.

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