Outer Membrane Vesicle-Host Cell Interactions

Cecil, Jessica D.; Sirisaengtaksin, Natalie; O'Brien-Simpson, Neil M; Krachler, Anne Marie

doi:10.1128/9781683670285.ch17

Cited by 35 publications

(54 citation statements)

References 126 publications

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“…All species (i.e., bacteria) in the oral cavity and the host can secrete nano-scaled extracellular vesicles (EVs) that circulate in saliva [27]. Gram-negative bacteria secreted EVs are named outer membrane vesicles (OMVs), and they play a vital role in intracellular communication, microbial virulence, and host immune response [28]. However, most studies have overlooked the detection of Gram-negative bacteria from saliva sEV, such as those from the periodontal pathogens T. forsythia, E. corrodens, P. gingivalis, P. anaerobius, and T. denticola.…”

Section: Effect Of Uc and Sec Isolation Methods On Salivary Sev Yield mentioning

confidence: 99%

Detection of Salivary Small Extracellular Vesicles Associated Inflammatory Cytokines Gene Methylation in Gingivitis

Han

Lai

Salomón

et al. 2020

IJMS

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Salivary small extracellular vesicles (sEV) are emerging as a potential liquid biopsy for oral diseases. However, technical difficulties for salivary sEV isolation remain a challenge. Twelve participants (five periodontally healthy, seven gingivitis patients) were recruited and salivary sEV were isolated by ultracentrifuge (UC-sEV) and size exclusion chromatography (SEC-sEV). The effect of UC and SEC on sEV yield, DNA methylation of five cytokine gene promoters (interleukin (IL)−6, tumor necrosis factor (TNF)-α, IL−1β, IL−8, and IL−10), and functional uptake by human primary gingival fibroblasts (hGFs) was investigated. The results demonstrated that SEC-sEV had a higher yield of particles and particle/protein ratios compared to UC-sEV, with a minimal effect on the detection of DNA methylation of five cytokine genes and functional uptake in hGFs (n = 3). Comparing salivary sEV characteristics between gingivitis and healthy patients, gingivitis-UC-sEV were increased compared to the healthy group; while no differences were found in sEV size, oral bacterial gDNA, and DNA methylation for five cytokine gene promoters, for both UC-sEV and SEC-sEV. Overall, the data indicate that SEC results in a higher yield of salivary sEV, with no significant differences in sEV DNA epigenetics, compared to UC.

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Section: Effect Of Uc and Sec Isolation Methods On Salivary Sev Yield mentioning

confidence: 99%

Detection of Salivary Small Extracellular Vesicles Associated Inflammatory Cytokines Gene Methylation in Gingivitis

Han

Lai

Salomón

et al. 2020

IJMS

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“…Therefore, secreted EVs from F. alocis may act as potent immune stimulators, leading to inflammation and bone loss in periodontal diseases. Moreover, EVs can deliver bioactive molecules to body sites (Cecil, Sirisaengtaksin, O'Brien‐Simpson, & Krachler, ) other than the oral cavity, possibly contributing to systemic diseases.…”

Section: Discussionmentioning

confidence: 99%

Characterization and immunostimulatory activity of extracellular vesicles from Filifactor alocis

Kim

Lim

et al. 2019

Molecular Oral Microbiology

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Filifactor alocis, a gram-positive, obligate anaerobic rod, is an emerging periodontal pathogen that is frequently isolated from patients with periodontitis, peri-implantitis, and apical periodontitis. Recent studies have shown that extracellular vesicles (EVs) from gram-negative periodontal pathogens, so-called outer membrane vesicles (OMVs), harbor various effector molecules responsible for inducing host inflammatory responses. However, there are no reports of EVs from F. alocis. In this study, we purified and characterized the protein profiles of EVs from F. alocis and investigated their immunostimulatory activity on human monocytic THP-1 and human oral keratinocyte HOK-16B cell lines. Highly pure EVs were obtained from F. alocis using density gradient ultracentrifugation. Nanoparticle tracking analysis and transmission electron microscopy showed that F. alocis EVs were between 50 and 270 nm in diameter. Proteome analysis identified 28 proteins, including lipoproteins, autolysins, F. alocis complement inhibitor (FACIN), transporter-related proteins, metabolism-related proteins, and ribosomal proteins. Human cytokine array analysis showed that F.alocis EVs remarkably induced the expression of CCL1, CCL2, MIP-1, CCL5, CXCL1, CXCL10, ICAM-1, IL-1β, IL-1ra, IL-6, IL-8, MIF, SerpinE, and TNF-α in THP-1 cells and CXCL1, G-CSF, GM-CSF, IL-6, and IL-8 in HOK-16B cells. The immunostimulatory activity of F. alocis EVs was similar to that of the whole bacterial cells. Our findings provide new insight into the role of EVs from gram-positive oral bacteria in periodontal diseases.

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“…Outer membrane vesicles carrying MAMPs are shed by Gram negative bacteria (Tashiro et al, 2010;Cecil et al, 2019). OMVs where harvested in the following way: An inoculum of Escherichia coli DH5α was inoculated to 10 ml 1/10 DFM medium (Ipcho et al, 2016) in a 50ml in a sterilized centrifuge tube and incubated over night at 28 o C. The bacterial cell harvested by centrifugation at 4200g for 5 minutes.…”

Section: Preparation Of Omvs As Mamps Source For No Productionmentioning

confidence: 99%

Evolutionary conserved multifunctional nitric oxide synthesis proteins responding to bacterial MAMPs are located at the endoplasmic reticulum

Zheng

Ipcho

et al. 2020

Preprint

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Nitric oxide is known to be produced by most Eukaryotic organisms although the NO production mechanism is only known for animals (Canovas et al., 2016). Mammals have a set of different nitric oxide synthases (NOSs) with basically similar mechanism for producing NO under different circumstances (Velayutham and Zweier, 2013; Yu et al., 2014). NO-production is characteristically induced as part of innate immunity reactions to bacterial Microbial Associated Molecular Patterns (MAMPs). We knew from our previous work that the plant pathogen Fusarium graminearum quickly upregulate genes characteristic for an innate immune response so we set out to test if it also produces NO as part of this response and find the responsible genes if it does. We found that F. graminearum produces NO in response to bacterial MAMPs and that the NO production system must be similar in fungi as in mammals where NO is activated by a homo-dimerization of nitric oxide synthase proteins (NOSs) containing an N-terminal cytochrome P450 domain (CYP) and a C-terminal NADPH dependent cytochrome P450 reductase (NCP) domain. The electrons are transferred from the C-terminal NCP domains to the CYP domain in the paired protein to produce NO. We could not find a candidate NOS in the fungus. Thus, we tested the hypothesis that an NCP-protein similar to the NCP part of a NOS is brought together with a CYP-protein to produce NO in another way than the dimerization of a classic NOS. We found that in F. graminearum NO is produced by an FgNCP and an FgCYP located to the endoplasmic reticulum membrane where both proteins are predicted to be N-terminally attached by a transmembrane or embedded hydrophobic alpha helix. Deletion of any of these proteins lowered pathogenicity to wheat and stopped NO-production. Knockout of the FgNCP also completely blocked deoxynivalenol synthesis needed for pathogenicity indicating that the FgNCP also delivers electrons to another CYP (TRI4) located at the ER. The FgCYP we found to be involved in NO-productions is the same or similar to proteins involved in Eukaryote sterol synthesis (CYP51) reducing lanosterol on the way to the final main sterols different for different Eukaryotes. Lanosterol enriched membranes are known to be inhibited in endocytosis and we found that the deletion of the FgCYP producing NO also completely stopped endocytosis. We further tested consequences of these indications of more than one function and suggest the CYP-protein is most likely an FgCYPNO,ERG involved in both NO and ergosterol synthesis and the NCP is involved in NO, trichothecene and ergosterol synthesis, an FgNCPNO,TRI,ERG. The two proteins shown here to be responsible for NO production in F. graminearum are both highly conserved in Eukaryotes from amoeba to human and homologues are likely candidates for the production of NO in many other eukaryotes including mammals. The multiple functions of these proteins can be part of the explanation for the links between chronic inflammation, sterols and blood pressure in human.

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Outer Membrane Vesicle-Host Cell Interactions

Cited by 35 publications

References 126 publications

Detection of Salivary Small Extracellular Vesicles Associated Inflammatory Cytokines Gene Methylation in Gingivitis

Detection of Salivary Small Extracellular Vesicles Associated Inflammatory Cytokines Gene Methylation in Gingivitis

Characterization and immunostimulatory activity of extracellular vesicles from Filifactor alocis

Evolutionary conserved multifunctional nitric oxide synthesis proteins responding to bacterial MAMPs are located at the endoplasmic reticulum

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