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Outer membrane vesicles

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https://www.readbyqxmd.com/read/28721849/effective-protection-of-mice-against-shigella-flexneri-with-a-new-self-adjuvant-multicomponent-vaccine
#1
Yadira Pastor, Ana Camacho, Ana Gloria Gil, Rocío Ramos, Adela López de Ceráin, Iván Peñuelas, Juan M Irache, Carlos Gamazo
PURPOSE: The aim of this study was to develop an immunogenic protective product against Shigella flexneri by employing a simple and safe heat treatment-based strategy. METHODOLOGY: The physicochemical characteristics of naturally produced (OMV) and heat-induced (HT) outer-membrane vesicles from S. flexneri were examined, including a comparison of the protein content of the products. Toxicological and biodistribution studies, and a preliminary experiment to examine the protective effectiveness of HT in a murine model of S...
July 18, 2017: Journal of Medical Microbiology
https://www.readbyqxmd.com/read/28717425/high-throughput-nanoparticle-tracking-analysis-for-monitoring-outer-membrane-vesicle-production
#2
Matthias J H Gerritzen, Dirk E Martens, René H Wijffels, Michiel Stork
Outer membrane vesicles (OMVs) are spherical membrane nanoparticles released by Gram-negative bacteria. OMVs can be quantified in complex matrices by nanoparticle tracking analysis (NTA). NTA can be performed in static mode or with continuous sample flow that results in analysis of more particles in a smaller time-frame. Flow measurements must be performed manually despite the availability of a sample changer on the NanoSight system. Here we present a method for automated measurements in flow mode. OMV quantification in flow mode results in lower variance in particle quantification (coefficient of variation (CV) of 6%, CV static measurements of 14%)...
2017: Journal of Extracellular Vesicles
https://www.readbyqxmd.com/read/28717032/th17-mediated-cross-protection-against-pneumococcal-carriage-by-vaccination-with-a-variable-antigen
#3
Kirsten Kuipers, Wouter S P Jong, Christa E van der Gaast-de Jongh, Diane Houben, Fred van Opzeeland, Elles Simonetti, Saskia van Selm, Ronald de Groot, Marije I Koenders, Taj Azarian, Elder Pupo, Peter van der Ley, Jeroen D Langereis, Aldert Zomer, Joen Luirink, Marien I de Jonge
Serotype-specific protection against a Streptococcus pneumoniae is an important limitation of the current polysaccharide-based vaccines. To prevent serotype replacement, reduce transmission and limit emergence of new variants, it is essential to induce broad protection and restrict pneumococcal colonization. In this study, we used a prototype vaccine formulation consisting of LPS-detoxified outer membrane vesicles (OMVs) from Salmonella Typhimurium displaying the variable N-terminus of PspA (α1α2) for intranasal vaccination, which induced strong Th17 immunity associated with substantial reduction of pneumococcal colonization...
July 17, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28705462/effectiveness-of-a-group-b-outer-membrane-vesicle-meningococcal-vaccine-against-gonorrhoea-in-new-zealand-a-retrospective-case-control-study
#4
Helen Petousis-Harris, Janine Paynter, Jane Morgan, Peter Saxton, Barbara McArdle, Felicity Goodyear-Smith, Steven Black
BACKGROUND: Gonorrhoea is a major global public health problem that is exacerbated by drug resistance. Effective vaccine development has been unsuccessful, but surveillance data suggest that outer membrane vesicle meningococcal group B vaccines affect the incidence of gonorrhoea. We assessed vaccine effectiveness of the outer membrane vesicle meningococcal B vaccine (MeNZB) against gonorrhoea in young adults aged 15-30 years in New Zealand. METHODS: We did a retrospective case-control study of patients at sexual health clinics aged 15-30 years who were born between Jan 1, 1984, and Dec 31, 1998, eligible to receive MeNZB, and diagnosed with gonorrhoea or chlamydia, or both...
July 7, 2017: Lancet
https://www.readbyqxmd.com/read/28701394/single-particle-detection-of-transcription-following-rotavirus-entry
#5
Eric N Salgado, Srigokul Upadhyayula, Stephen C Harrison
Infectious rotavirus particles are triple-layered, icosahedral assemblies. The outer layer proteins, VP4 (cleaved to VP8* and VP5*) and VP7, surround a transcriptionally competent, double-layer particle (DLP), which they deliver into the cytosol. During entry of rhesus rotavirus, VP8* interacts with cell-surface gangliosides, allowing engulfment into a membrane vesicle by a clathrin-independent process. Escape into the cytosol and outer-layer shedding depend on interaction of a hydrophobic surface on VP5* with the membrane bilayer and on a large-scale conformational change...
July 12, 2017: Journal of Virology
https://www.readbyqxmd.com/read/28696280/nontypeable-haemophilus-influenzae-releases-dna-and-dnabii-proteins-via-a-t4ss-like-complex-and-come-of-the-type-iv-pilus-machinery
#6
Joseph A Jurcisek, Kenneth L Brockman, Laura A Novotny, Steven D Goodman, Lauren O Bakaletz
Biofilms formed by nontypeable Haemophilus influenzae (NTHI) are central to the chronicity, recurrence, and resistance to treatment of multiple human respiratory tract diseases including otitis media, chronic rhinosinusitis, and exacerbations of both cystic fibrosis and chronic obstructive pulmonary disease. Extracellular DNA (eDNA) and associated DNABII proteins are essential to the overall architecture and structural integrity of biofilms formed by NTHI and all other bacterial pathogens tested to date. Although cell lysis and outer-membrane vesicle extrusion are possible means by which these canonically intracellular components might be released into the extracellular environment for incorporation into the biofilm matrix, we hypothesized that NTHI additionally used a mechanism of active DNA release...
July 10, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28694488/outer-membrane-vesicles-secreted-by-pathogenic-and-nonpathogenic-bacteroides-fragilis-represent-different-metabolic-activities
#7
Natalya B Zakharzhevskaya, Anna A Vanyushkina, Ilya A Altukhov, Aleksey L Shavarda, Ivan O Butenko, Daria V Rakitina, Anastasia S Nikitina, Aleksandr I Manolov, Alina N Egorova, Eugene E Kulikov, Innokentii E Vishnyakov, Gleb Y Fisunov, Vadim M Govorun
Numerous studies are devoted to the intestinal microbiota and intercellular communication maintaining homeostasis. In this regard, vesicles secreted by bacteria represent one of the most popular topics for research. For example, the outer membrane vesicles (OMVs) of Bacteroides fragilis play an important nutritional role with respect to other microorganisms and promote anti-inflammatory effects on immune cells. However, toxigenic B. fragilis (ETBF) contributes to bowel disease, even causing colon cancer. If nontoxigenic B...
July 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28686482/outer-membrane-vesicles-blebbing-contributes-to-b-vulgatus-mpk-mediated-immune-response-silencing
#8
Jan Kevin Maerz, Alex Steimle, Anna Lange, Annika Bender, Birgit Fehrenbacher, Julia-Stefanie Frick
The Gram negative intestinal symbiont Bacteroides vulgatus mpk is able to prevent from induction of colonic inflammation in Rag1(-/-) mice and promotes immune balance in Il2(-/-) mice. These inflammation-silencing effects are associated with B. vulgatus mpk-mediated induction of semi-mature dendritic cells, especially in the colonic lamina propria (cLP). However the beneficial interaction of bacteria with host immune cells is limited due to the existence of a large mucus layer covering the intestinal epithelium...
July 7, 2017: Gut Microbes
https://www.readbyqxmd.com/read/28676761/asymmetrical-polymer-vesicles-for-drug-delivery-and-other-applications
#9
REVIEW
Yi Zhao, Xiaoming Li, Xiaotian Zhao, Yunqi Yang, Hui Li, Xinbo Zhou, Weien Yuan
Scientists have been attracted by polymersomes as versatile drug delivery systems since the last two decades. Polymersomes have the potential to be versatile drug delivery systems because of their tunable membrane formulations, stabilities in vivo, various physicochemical properties, controlled release mechanisms, targeting abilities, and capacities to encapsulate a wide range of drugs and other molecules. Asymmetrical polymersomes are nano- to micro-sized polymeric capsules with asymmetrical membranes, which means, they have different outer and inner coronas so that they can exhibit better endocytosis rate and endosomal escape ability than other polymeric systems with symmetrical membranes...
2017: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/28675605/intrahost-milieu-modulates-production-of-outer-membrane-vesicles-vesicle-associated-shiga-toxin-2a-and-cytotoxicity-in-escherichia-coli-o157-h7-and-o104-h4
#10
Andreas Bauwens, Lisa Kunsmann, Monika Marejková, Wenlan Zhang, Helge Karch, Martina Bielaszewska, Alexander Mellmann
Outer membrane vesicles (OMVs) are important virulence tools of enterohaemorrhagic Escherichia coli (EHEC), but other biological functions of these nanostructures are unknown. We tested the hypothesis that modulation of OMV production enables EHEC to resist the intrahost environment during infection by investigating if simulated human gastrointestinal conditions affect OMV production in EHEC O157:H7 and O104:H4. All the conditions tested including a low pH, simulated ileal and colonic media, presence of mucin, intestinal epithelial cell lysate or antimicrobial peptides, as well as iron limitation, significantly increased OMV production by these pathogens...
July 4, 2017: Environmental Microbiology Reports
https://www.readbyqxmd.com/read/28670574/corrigendum-interaction-of-bacteroides-fragilis-toxin-with-outer-membrane-vesicles-reveals-new-mechanism-of-its-secretion-and-delivery
#11
Natalya B Zakharzhevskaya, Vladimir B Tsvetkov, Anna A Vanyushkina, Anna M Varizhuk, Daria V Rakitina, Victor V Podgorsky, Innokentii E Vishnyakov, Daria D Kharlampieva, Valentin A Manuvera, Fedor V Lisitsyn, Elena A Gushina, Vassili N Lazarev, Vadim M Govorun
[This corrects the article on p. 2 in vol. 7, PMID: 28144586.].
2017: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/28666873/overexpression-of-mica-induces-production-of-ompc-enriched-outer-membrane-vesicles-that-protect-against-salmonella-challenge
#12
Hyun-Il Choi, Moonjeong Kim, Jinseong Jeon, Jin Kwan Han, Kwang-Sun Kim
Outer membrane vesicles (OMVs) derived from bacteria are promising candidates for subunit vaccines. Stresses that modulate the composition of outer membrane proteins (OMPs) are important for OMV synthesis. Small RNAs (sRNAs) expressed in response to stress regulate OMPs, although the mechanism underlying sRNA-mediated OMV biogenesis and its utility for developing vaccine platforms remains to be elucidated. Here, we characterized the role of a sRNA, MicA, which regulates OmpA, a major OMP involved in both production of OMVs and reactive immunity against Salmonella challenge...
June 27, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/28660582/single-step-capture-and-targeted-metabolomics-of-alkyl-quinolones-in-outer-membrane-vesicles-of-pseudomonas-aeruginosa
#13
Pallavi Lahiri, Dipankar Ghosh
Outer membrane vesicles (OMVs) are secreted by all Gram-ve pathogens. These nano-scale delivery vehicles contain discrete arrays of prokaryotic pathogenic determinants, including a family of low molecular weight (MW) lipidic quorum signaling alkyl-quinolones (AQs). These are synthesized from β-keto-fatty acids and function like primordial lipidic hormones, which regulate numerous pathogenic factors both inter-species and intra-species. Significantly, AQs can also directly exacerbate pathogenesis by cross-kingdom signaling with the host immune, metabolic, and other systems...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28650960/phosphatidylserine-externalization-necroptotic-bodies-release-and-phagocytosis-during-necroptosis
#14
Sefi Zargarian, Inbar Shlomovitz, Ziv Erlich, Aria Hourizadeh, Yifat Ofir-Birin, Ben A Croker, Neta Regev-Rudzki, Liat Edry-Botzer, Motti Gerlic
Necroptosis is a regulated, nonapoptotic form of cell death initiated by receptor-interacting protein kinase-3 (RIPK3) and mixed lineage kinase domain-like (MLKL) proteins. It is considered to be a form of regulated necrosis, and, by lacking the "find me" and "eat me" signals that are a feature of apoptosis, necroptosis is considered to be inflammatory. One such "eat me" signal observed during apoptosis is the exposure of phosphatidylserine (PS) on the outer plasma membrane. Here, we demonstrate that necroptotic cells also expose PS after phosphorylated mixed lineage kinase-like (pMLKL) translocation to the membrane...
June 2017: PLoS Biology
https://www.readbyqxmd.com/read/28649237/outer-membrane-vesicles-omvs-of-gram-negative-bacteria-a-perspective-update
#15
REVIEW
Arif Tasleem Jan
Outer Membrane Vesicles (OMVs) of Gram-negative bacteria are spherical membrane-enclosed entities of endocytic origin. Reported in the consortia of different bacterial species, production of OMVs into extracellular milieu seems essential for their survival. Enriched with bioactive proteins, toxins, and virulence factors, OMVs play a critical role in the bacteria-bacteria and bacteria-host interactions. Emergence of OMVs as distinct cellular entities helps bacteria in adaptating to diverse niches, in competing with other bacteria to protect members of producer species and more importantly play a crucial role in host-pathogen interaction...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28647061/vesicle-fusion-mediated-by-solanesol-anchored-dna
#16
Kristina M Flavier, Steven G Boxer
Fusion between two lipid bilayers is one of the central processes in cell biology, playing a key role in endocytosis, exocytosis, and vesicle transport. We have previously developed a model system that uses the hybridization of complementary DNA strands to model the formation of the SNARE four-helix bundle that mediates synaptic vesicle fusion and used it to study vesicle fusion to a tethered lipid bilayer. Using single vesicle assays, 70% of observed fusion events in the DNA-lipid system are arrested at the hemifusion stage, whereas only 5% eventually go to full fusion...
June 21, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28636010/engineering-multi-functional-bacterial-outer-membrane-vesicles-as-modular-nanodevices-for-biosensing-and-bioimaging
#17
Qi Chen, Sharon Rozovsky, Wilfred Chen
Outer membrane vesicles (OMVs) are proteoliposomes derived from the outer membrane and periplasmic space of many Gram-negative bacteria including E. coli as part of their natural growth cycle. Inspired by the natural ability of E. coli to sort proteins to both the exterior and interior of OMVs, we reported here a one-pot synthesis approach to engineer multi-functionalized OMV-based sensors for both antigen binding and signal generation. SlyB, a native lipoprotein, was used a fusion partner to package nanoluciferase (Nluc) within OMVs, while a previously developed INP-Scaf3 surface scaffold was fused to the Z-domain for antibody recruiting...
July 4, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28624305/durability-of-immunogenicity-and-strain-coverage-of-menbvac-a-meningococcal-vaccine-based-on-outer-membrane-vesicles-lessons-of-the-normandy-campaign
#18
Julien Sevestre, Eva Hong, Valérie Delbos, Aude Terrade, Eric Mallet, Ala-Eddine Deghmane, Ludovic Lemée, Muhamed-Kheir Taha, François Caron
OBJECTIVES: MenBvac® is an outer membrane vesicle (OMV)-based meningococcal vaccine. From 2006 to 2012, it was used to control a clonal B outbreak in Normandy (France). We aimed to analyse the durability of the response against the epidemic strain and coverage beyond the vaccine strain. These data should help to optimize the use of OMV-containing vaccines, such as the new 4CMenB/Bexsero® recombinant vaccine. METHODS: Serum bactericidal activity (SBA) was measured in two cohorts of children who received their first dose of MenBvac® at 1-5years of age and accepted to provide a blood sample either one or four years after a 2+1+1 schedule...
July 13, 2017: Vaccine
https://www.readbyqxmd.com/read/28622430/enterohaemorrhagic-escherichia-coli-produces-outer-membrane-vesicles-as-an-active-defense-system-against-antimicrobial-peptide-ll-37
#19
Akiko Urashima, Ayano Sanou, Hilo Yen, Toru Tobe
Antimicrobial peptides (AMPs) are important components of the innate immune system. Enterohaemorrhagic Escherichia coli (EHEC), a food-borne pathogen causing serious diarrheal diseases, must overcome attack by AMPs. Here, we show that resistance of EHEC against human cathelicidin LL-37, a primary AMP, was enhanced by butyrate, which has been shown to act as a stimulant for the expression of virulence genes. The increase of resistance depended on the activation of the ompT gene, which encodes the outer membrane protease OmpT for LL-37...
June 16, 2017: Cellular Microbiology
https://www.readbyqxmd.com/read/28609638/hyperbiofilm-phenotype-of-pseudomonas-aeruginosa-defective-for-the-plcb-and-plcn-secreted-phospholipases
#20
Shawn Lewenza, Laetitia Mazenod, Shirin Afroj, Erik van Tilburg Bernardes
Biofilms are dense communities of bacteria enmeshed in a protective extracellular matrix composed mainly of exopolysaccharides (EPS), extracellular DNA (eDNA), proteins and outer membrane vesicles (OMV). Given the role of biofilms in antibiotic tolerant and chronic infections, novel strategies are needed to block, disperse or degrade biofilms. Enzymes that degrade the biofilm matrix are a promising new therapy. We screened mutants in many of the enzymes secreted by the type II secretion system (T2SS) and determined that the T2SS, and specifically phospholipases, play a role in biofilm formation...
June 13, 2017: Canadian Journal of Microbiology
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