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Outer membrane vesicles

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https://www.readbyqxmd.com/read/28636010/engineering-multi-functional-bacterial-outer-membrane-vesicles-as-modular-nanodevices-for-biosensing-and-bioimaging
#1
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...
June 21, 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
#2
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...
June 14, 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
#3
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
#4
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
https://www.readbyqxmd.com/read/28607018/antibiotic-mediated-modulations-of-outer-membrane-vesicles-in-enterohemorrhagic-escherichia-coli-o104-h4-and-o157-h7
#5
Andreas Bauwens, Lisa Kunsmann, Helge Karch, Alexander Mellmann, Martina Bielaszewska
Ciprofloxacin, meropenem, fosfomycin, and polymyxin B strongly increase production of outer membrane vesicles (OMVs) in Escherichia coli O104:H4 and O157:H7. Ciprofloxacin also upregulates OMV-associated Shiga toxin 2a, the major virulence factor of these pathogens, whereas the other antibiotics increase OMV production without the toxin. Both these effects might worsen the clinical outcome of infections caused by Shiga toxin-producing E. coli Our data support the existing recommendations to avoid antibiotics for treatment of these infections...
June 12, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28596142/amphiphilic-cyclodextrin-nanoparticles
#6
Gamze Varan, Cem Varan, Nazlı Erdoğar, A Atilla Hıncal, Erem Bilensoy
Cyclodextrins are cyclic oligosaccharides obtained by enzymatic digestion of starch. The α-, β- and γ- cyclodextrins contain respectively 6, 7 and 8 glucopyranose units, with primary and secondary hydroxyl groups located on the narrow and wider rims of a truncated cone shape structure. Such structure is that of a hydrophobic inner cavity with a hydrophilic outer surface allowing to interact with a wide range of molecules like ions, protein and oligonucleotides to form inclusion complexes. Many cyclodextrin applications in the pharmaceutical area have been widely described in the literature due to their low toxicity and low immunogenicity...
June 5, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28592876/elongation-factor-tu-on-escherichia-coli-isolated-from-urine-of-kidney-stone-patients-promotes-calcium-oxalate-crystal-growth-and-aggregation
#7
Piyawan Amimanan, Ratree Tavichakorntrakool, Kedsarin Fong-Ngern, Pipat Sribenjalux, Aroonlug Lulitanond, Vitoon Prasongwatana, Chaisiri Wongkham, Patcharee Boonsiri, Jariya Umka Welbat, Visith Thongboonkerd
Escherichia coli is the most common bacterium isolated from urine and stone matrix of calcium oxalate (CaOx) stone formers. Whether it has pathogenic role(s) in kidney stone formation or is only entrapped inside the stone remains unclear. We thus evaluated differences between E. coli isolated from urine of patients with kidney stone (EUK) and that from patients with urinary tract infection (UTI) without stone (EUU). From 100 stone formers and 200 UTI patients, only four pairs of EUK/EUU isolates had identical antimicrobial susceptibility patterns...
June 7, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28579961/characterization-of-annexin-v-fusion-with-the-superfolder-gfp-in-liposomes-binding-and-apoptosis-detection
#8
Abdul Qader Abbady, Aya Twair, Bouthaina Ali, Hossam Murad
Programed cell death is a critical and unavoidable part of life. One of the most widely used markers for dying cells, by apoptosis or pyroptosis, is the redistribution of phosphatidylserine (PS) from the inner to the outer plasma membrane leaflet. Annexin V protein is a sensitive and specific probe to mark this event because of its high affinity to the exposed PS. Beyond that, annexin V can bind to any PS-containing phospholipid bilayer of almost all tiny forms of membranous vesicles like blood platelets, exosomes, or even nanostructured liposomes...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28576571/nontoxic-outer-membrane-vesicles-efficiently-increase-the-efficacy-of-an-influenza-vaccine-in-mice-and-ferrets
#9
Sang-Mu Shim, Eun-Jung Song, Daesub Song, Tae-Young Lee, Doo-Jin Kim, Jeong-Hyun Nam, Dae Gwin Jeong, Chong-Kil Lee, Sang-Hyun Kim, Jeong-Ki Kim
In this study, we developed a further-modified outer membrane vesicle (fmOMV) from the ΔmsbB/ΔpagP mutant of Escherichia coli transformed with the plasmid, pLpxF, in order to use it as an adjuvant for pandemic H1N1 (pH1N1) influenza vaccine. We evaluated the efficacy of the pH1N1 influenza vaccine containing the fmOMV in animal models as compared to the commercial adjuvants, alum or AddaVax(TM). The fmOMV-adjuvanted pH1N1 influenza vaccine induced a significant increase in the humoral immunity; however, this effect was less than that of the AddaVax(TM)...
May 30, 2017: Vaccine
https://www.readbyqxmd.com/read/28570683/bacterial-outer-membrane-vesicles-at-the-plant-pathogen-interface
#10
Leron Katsir, Ofir Bahar
No abstract text is available yet for this article.
June 2017: PLoS Pathogens
https://www.readbyqxmd.com/read/28564579/lipid-membranes-catalyse-the-fibril-formation-of-the-amyloid-%C3%AE-1-42-peptide-through-lipid-fibril-interactions-that-reinforce-secondary-pathways
#11
David J Lindberg, Emelie Wesén, Johan Björkeroth, Sandra Rocha, Elin K Esbjörner
Alzheimer's disease is associated with the aggregation of amyloid-β (Aβ) peptides into oligomers and fibrils. Herein we explore how model lipid membranes modulate the rate and mechanisms of Aβ(1-42) self-assembly, in order to shed light on how this pathological reaction, may occur in the lipid-rich environments that this peptide encounters in the brain. Using a combination of in vitro biophysical experiments and theoretical approaches, we show that zwitterionic lipid vesicles accelerate the Aβ(1-42) fibril growth rate by interacting specifically with the growing fibrils...
May 28, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28551523/digitonin-does-not-flip-across-cholesterol-poor-membranes
#12
Helen Y Fan, Heiko Heerklotz
Digitonin is commonly used to permeabilize cell membranes and solubilize membrane components. It interacts specifically with cholesterol in the membrane which leads to the formation of pores. Thus far, the mechanism by which digitonin interacts with the membrane has only been described qualitatively. We investigated this interaction in model membranes that contain little or no cholesterol with a combination of isothermal titration calorimetry, dynamic light scattering, and zeta potential measurements. Digitonin partitions fully asymmetrically into large unilamellar vesicles of phosphocholine (PC) lipid at 20°C (remaining in the outer leaflet only), with a partition coefficient of 0...
May 17, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28545924/retinoic-acid-pre-treatment-down-regulates-v-cholerae-outer-membrane-vesicles-induced-acute-inflammation-and-enhances-mucosal-immunity
#13
Ritam Sinha, Debaki Ranjan Howlader, Atri Ta, Soma Mitra, Santasabuj Das, Hemanta Koley
Bacterial outer membrane vesicles have been extensively investigated and considered as a next generation vaccine. Recently, we have demonstrated that the cholera pentavalent outer membrane vesicles (CPMVs) immunogen induced adaptive immunity and had a strong protective efficacy against the circulating V. cholerae strains in a mouse model. In this present study, we are mainly focusing on reducing outer membrane vesicle (OMV) -mediated toxicity without altering its antigenic property. Therefore, we have selected All-trans Retinoic Acid (ATRA), active metabolites of vitamin A, which have both anti-inflammatory and mucosal adjuvant properties...
June 16, 2017: Vaccine
https://www.readbyqxmd.com/read/28539041/outer-membrane-vesicles-derived-from-salmonella-enteritidis-protect-against-the-virulent-wild-type-strain-infection-in-a-mouse-model
#14
Qiong Liu, Jie Yi, Kang Liang, Xiangmin Zhang, Qing Liu
Food-borne contamination and salmonellosis caused by Salmonella Enteritidis (S. Enteritidis) are a significant threat to human health and poultry enterprises. Outer membrane vesicles (OMVs), which are naturally secreted by gram-negative bacteria, could be a good vaccine option because they have many biologically active substances, including lipopolysaccharides (LPS), outer membrane proteins (OMPs), and phospholipids, as well as periplasmic components. In the present study, we purified OMVs derived from S. Enteritidis and analyzed their characteristics through silver staining and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE)...
May 25, 2017: Journal of Microbiology and Biotechnology
https://www.readbyqxmd.com/read/28538152/apoptotic-bax-at-oxidatively-stressed-mitochondrial-membranes-lipid-dynamics-and-permeabilization
#15
Artur Peter Günther Dingeldein, Šárka Pokorná, Martin Lidman, Tobias Sparrman, Radek Šachl, Martin Hof, Gerhard Gröbner
Mitochondria are crucial compartments of eukaryotic cells because they function as the cellular power plant and play a central role in the early stages of programmed cell death (apoptosis). To avoid undesired cell death, this apoptotic pathway is tightly regulated by members of the Bcl-2 protein family, which interact on the external surface of the mitochondria, i.e., the mitochondrial outer membrane (MOM), and modulate its permeability to apoptotic factors, controlling their release into the cytosol. A growing body of evidence suggests that the MOM lipids play active roles in this permeabilization process...
May 23, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28530169/commensal-derived-omvs-elicit-a-mild-proinflammatory-response-in-intestinal-epithelial-cells
#16
Daniel A Patten, Enas Hussein, Scott P Davies, Paul N Humphreys, Andrew Collett
Under normal physiological conditions, the intestinal immunity remains largely hyporesponsive to the commensal microbiota, yet also retains the inherent ability to rapidly respond to pathogenic antigens. However, immunomodulatory activities of extracellular products from commensal bacteria have been little studied, with previous investigations generally utilizing the live bacterium to study microbiota-epithelial interactions. In this study, we demonstrate that extracellular products of a commensal bacterium, Escherichia coli C25, elicit a moderate release of proinflammatory IL-8 and stimulate transcriptional up-regulation of Toll-like receptors (TLRs) in intestinal epithelial cell lines HT29-19A and Caco-2...
May 2017: Microbiology
https://www.readbyqxmd.com/read/28522212/bioengineering-bacterial-outer-membrane-vesicles-as-vaccine-platform
#17
REVIEW
Matthias J H Gerritzen, Dirk E Martens, René H Wijffels, Leo van der Pol, Michiel Stork
Outer membrane vesicles (OMVs) are naturally non-replicating, highly immunogenic spherical nanoparticles derived from Gram-negative bacteria. OMVs from pathogenic bacteria have been successfully used as vaccines against bacterial meningitis and sepsis among others and the composition of the vesicles can easily be engineered. OMVs can be used as a vaccine platform by engineering heterologous antigens to the vesicles. The major advantages of adding heterologous proteins to the OMV are that the antigens retain their native conformation, the ability of targeting specific immune responses, and a single production process suffices for many vaccines...
May 15, 2017: Biotechnology Advances
https://www.readbyqxmd.com/read/28505330/acinetobacter-baumannii-transfers-the-blandm-1-gene-via-outer-membrane-vesicles
#18
Somdatta Chatterjee, Ayan Mondal, Shravani Mitra, Sulagna Basu
Objectives: To investigate the transmission of the gene encoding New Delhi metallo-β-lactamase-1 ( bla NDM-1 ) through outer membrane vesicles (OMVs) released from an Acinetobacter baumannii strain (A_115). Methods: Isolation and purification of OMVs by density gradient from a carbapenem-resistant clinical strain of A. baumannii harbouring plasmid-mediated bla NDM-1 and aac(6')-Ib-cr genes was performed. DNA was purified from the OMVs and used for PCR and dot-blot analysis...
May 12, 2017: Journal of Antimicrobial Chemotherapy
https://www.readbyqxmd.com/read/28501509/designer-outer-membrane-vesicles-as-immunomodulatory-systems-reprogramming-bacteria-for-vaccine-delivery
#19
Yehou M D Gnopo, Hannah C Watkins, Taylor C Stevenson, Matthew P DeLisa, David Putnam
Vaccines often require adjuvants to be effective. Traditional adjuvants, like alum, activate the immune response but in an uncontrolled way. Newer adjuvants help to direct the immune response in a more coordinated fashion. Here, we review the opportunity to use the outer membrane vesicles (OMVs) of bacteria as a way to modulate the immune response toward making more effective vaccines. This review outlines the different types of OMVs that have been investigated for vaccine delivery and how they are produced...
May 10, 2017: Advanced Drug Delivery Reviews
https://www.readbyqxmd.com/read/28495657/outer-membrane-vesicles-extracted-from-neisseria-meningitidis-serogroup-x-for-prevention-of-meningococcal-disease-in-africa
#20
Reinaldo Acevedo, Caridad Zayas, Gunnstein Norheim, Sonsire Fernández, Barbara Cedré, Yisabel Aranguren, Maribel Cuello, Yaimara Rodriguez, Humberto González, Aleida Mandiarote, Marylin Pérez, Maritza Hernández, Mabel Hernández-Cedeño, Domingo González, Sverre-Henning Brorson, Einar Rosenqvist, Lisbeth Naess, Gro Tunheim, Daniel Cardoso, Luis García
Meningococcal disease is caused mainly by serogroups A, B, C, Y, W of N. meningitidis. However, numerous cases of meningitis caused by serogroup X N. meningitidis (MenX) have recently been reported in several African countries. Currently, there are no licensed vaccines against this pathogen and most of the MenX cases have been caused by meningococci from clonal complex (c.c) 181. Detergent extracted meningococcal outer membrane vesicle (dOMV) vaccines have previously shown to be safe and effective against epidemics of serogroup B meningococcal disease in all age groups...
May 8, 2017: Pharmacological Research: the Official Journal of the Italian Pharmacological Society
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