PMAP-36 reduces the innate immune response induced by Bordetella bronchiseptica-derived outer membrane vesicles

Host cell membrane rearrangements induced by the hepatitis C virus (HCV) have been exclusively studied in vitro. These studies have shown that HCV induces double-membrane vesicles (DMVs), which probably serve to separate replication sites from the cytoplasmic sensors of the innate immune response. We report for the first time the observation of HCV-induced membrane rearrangements in liver biopsy specimens from patients chronically infected with HCV. Unlike observations performed in vitro, the membranous web detected in liver tissue seems essentially made of clusters of single-membrane vesicles derived from the endoplasmic reticulum and close to lipid droplets. This suggests that the DMVs could be a hallmark of laboratory-adapted HCV strains, possibly due to their ability to achieve a high level of replication. Alternatively, the concealment of viral RNA in DMVs may be part of innate immune response mechanisms particularly developed in hepatoma cell lines cultured in vitro. In any case, this constitutes the first report showing the differences in the membranous web established by HCV in vitro and in vivo.

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Characterization of Innate Immune Responses of Human Endothelial Cells Induced by Porphyromonas gingivalis and Their Derived Outer Membrane Vesicles

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2016.00139 ◽

2016 ◽

Vol 6 ◽

Cited By ~ 7

Author(s):

Meng-Hsuan Ho ◽

Zhong-Mao Guo ◽

Julio Chunga ◽

J. Shawn Goodwin ◽

Hua Xie

Keyword(s):

Endothelial Cells ◽

Immune Responses ◽

Outer Membrane ◽

Porphyromonas Gingivalis ◽

Membrane Vesicles ◽

Outer Membrane Vesicles ◽

Innate Immune ◽

Innate Immune Responses ◽

Human Endothelial Cells

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Bacterial Outer Membrane Vesicles Induce Plant Immune Responses

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-12-15-0270-r ◽

2016 ◽

Vol 29 (5) ◽

pp. 374-384 ◽

Cited By ~ 24

Author(s):

Ofir Bahar ◽

Gideon Mordukhovich ◽

Dee Dee Luu ◽

Benjamin Schwessinger ◽

Arsalan Daudi ◽

...

Keyword(s):

Immune Response ◽

Outer Membrane ◽

Plant Pathogens ◽

Cell Communication ◽

Membrane Vesicles ◽

Outer Membrane Vesicles ◽

Defense Gene Expression ◽

Defense Gene ◽

Bacterial Communication ◽

Multiple Processes

Gram-negative bacteria continuously pinch off portions of their outer membrane, releasing membrane vesicles. These outer membrane vesicles (OMVs) are involved in multiple processes including cell-to-cell communication, biofilm formation, stress tolerance, horizontal gene transfer, and virulence. OMVs are also known modulators of the mammalian immune response. Despite the well-documented role of OMVs in mammalian-bacterial communication, their interaction with plants is not well studied. To examine whether OMVs of plant pathogens modulate the plant immune response, we purified OMVs from four different plant pathogens and used them to treat Arabidopsis thaliana. OMVs rapidly induced a reactive oxygen species burst, medium alkalinization, and defense gene expression in A. thaliana leaf discs, cell cultures, and seedlings, respectively. Western blot analysis revealed that EF-Tu is present in OMVs and that it serves as an elicitor of the plant immune response in this form. Our results further show that the immune coreceptors BAK1 and SOBIR1 mediate OMV perception and response. Taken together, our results demonstrate that plants can detect and respond to OMV-associated molecules by activation of their immune system, revealing a new facet of plant-bacterial interactions.

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Outer membrane vesicles blebbing contributes to B. vulgatus mpk-mediated immune response silencing

Gut Microbes ◽

10.1080/19490976.2017.1344810 ◽

2017 ◽

Vol 9 (1) ◽

pp. 1-12 ◽

Cited By ~ 20

Author(s):

Jan Kevin Maerz ◽

Alex Steimle ◽

Anna Lange ◽

Annika Bender ◽

Birgit Fehrenbacher ◽

...

Keyword(s):

Immune Response ◽

Outer Membrane ◽

Membrane Vesicles ◽

Outer Membrane Vesicles

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Sphingolipid Containing Outer Membrane Vesicles Serve as a Delivery Vehicle to Limit Host Immune Response to Porphyromonas gingivalis

10.1101/2020.10.05.327544 ◽

2020 ◽

Author(s):

Fernanda G. Rocha ◽

Gregory Ottenberg ◽

Zavier G. Eure ◽

Mary E. Davey ◽

Frank C. Gibson

Keyword(s):

Immune Response ◽

Inflammatory Response ◽

Outer Membrane ◽

Porphyromonas Gingivalis ◽

Membrane Vesicles ◽

Outer Membrane Vesicles ◽

Delivery Vehicle ◽

Cellular Inflammatory Response ◽

Elevated Expression ◽

Host Inflammatory Response

ABSTRACTSphingolipids (SLs) are essential structural components of mammalian cell membranes. Our group recently determined that the oral anaerobe Porphyromonas gingivalis delivers its SLs to host cells, and that the ability of P. gingivalis to synthesize SLs limits the elicited host inflammatory response during cellular infection. As P. gingivalis robustly produces outer membrane vesicles (OMVs), we hypothesized that OMVs serve as a delivery vehicle for SLs, that the SL status of the OMVs may impact cargo loading to OMVs, and that SL-containing OMVs limit elicited host inflammation similar to that observed by direct bacterial challenge. Transwell cell culture experiments determined that in comparison to the parent strain W83, the SL-null mutant elicited a hyper-inflammatory immune response from THP-1 macrophage-like cells with elevated TNF-α, IL-1β, and IL-6. Targeted assessment of Toll-like receptors (TLRs) identified elevated expression of TLR2, unchanged TLR4, and elevated expression of the adaptor molecules MyD88 and TRIF by SL-null P. gingivalis. No significant differences in gingipain activity were observed in our infection models and both strains produced OMVs of similar size. Using comparative 2-dimensional gel electrophoresis we identified differences in the protein cargo of the OMVs between parent and SL-null strain. Importantly, use of purified OMVs recapitulated the cellular inflammatory response observed in the transwell system with whole bacteria. These findings provide new insights into the role of SLs in P. gingivalis OMV cargo assembly and expand our understanding of SL-OMVs as bacterial structures that modulate the host inflammatory response.

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Immunogenicity of Intranasally Administered Meningococcal Native Outer Membrane Vesicles in Mice

Infection and Immunity ◽

10.1128/iai.67.1.113-119.1999 ◽

1999 ◽

Vol 67 (1) ◽

pp. 113-119 ◽

Cited By ~ 66

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.

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

Indian Journal of Animal Research ◽

10.18805/ijar.b-3428 ◽

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.

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