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Outer membrane vesicles

Matias Fingermann, Lucía Avila, Maria Belén De Marco, Luciana Vázquez, Darío Nicolás Di Biase, Andrea Verónica Müller, Mirta Lescano, José Christian Dokmetjian, Sonsire Fernández Castillo, José Luis Pérez Quiñoy
Strains of Shiga toxin-producing Escherichia coli (STEC) can cause the severe Hemolytic Uremic Syndrome (HUS). Shiga toxins are protein toxins that bind and kill microvascular cells, damaging vital organs. No specific therapeutics or vaccines have been licensed for use in humans yet. The most common route of infection is by consumption of dairy or farm products contaminated with STEC. Domestic cattle colonized by STEC strains represent the main reservoir, and thus a source of contamination. Outer Membrane Vesicles (OMV) obtained after detergent treatment of gram-negative bacteria have been used over the past decades for producing many licensed vaccines...
June 20, 2018: Human Vaccines & Immunotherapeutics
Francesca Micoli, Roberto Adamo, Paolo Costantino
Currently licensed glycoconjugate vaccines are composed of a carbohydrate moiety covalently linked to a protein carrier. Polysaccharides are T-cell independent antigens able to directly stimulate B cells to produce antibodies. Disease burden caused by polysaccharide-encapsulated bacteria is highest in the first year of life, where plain polysaccharides are not generally immunogenic, limiting their use as vaccines. This limitation has been overcome by covalent coupling carbohydrate antigens to proteins that provide T cell epitopes...
June 15, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Andreia Hanada Otake, Renata de Freitas Saito, Ana Paula Marques Duarte, Alexandre Ferreira Ramos, Roger Chammas
Melanomas often accumulate gangliosides, sialic acid-containing glycosphingolipids found in the outer leaflet of plasma membranes, as disialoganglioside GD3 and its derivatives. Here, we have transfected the GD3 synthase gene (ST8Sia I) in a normal melanocyte cell line in order to evaluate changes in the biological behavior of non-transformed cells. GD3 -synthase expressing cells converted GM3 into GD3 and accumulated both GD3 and its acetylated form, 9-O-acetyl-GD3 . Melanocytes were rendered more migratory on laminin-1 surfaces...
June 13, 2018: Biochimica et Biophysica Acta
Colin Crump
The assembly and egress of herpes simplex virus (HSV) is a complicated multistage process that involves several different cellular compartments and the activity of many viral and cellular proteins. The process begins in the nucleus, with capsid assembly followed by genome packaging into the preformed capsids. The DNA-filled capsids (nucleocapsids) then exit the nucleus by a process of envelopment at the inner nuclear membrane followed by fusion with the outer nuclear membrane. In the cytoplasm nucleocapsids associate with tegument proteins, which form a complicated protein network that links the nucleocapsid to the cytoplasmic domains of viral envelope proteins...
2018: Advances in Experimental Medicine and Biology
Giorgio Gabarrini, Rick Heida, Nienke van Ieperen, Mike A Curtis, Arie Jan van Winkelhoff, Jan Maarten van Dijl
The periodontal pathogen Porphyromonas gingivalis has been invoked in the autoimmune disease rheumatoid arthritis (RA). This association relates to the peptidylarginine deiminase of P. gingivalis (PPAD), an enzyme capable of citrullinating human proteins and potentially contributing to loss of tolerance to citrullinated proteins in RA. PPAD is both retained in the outer membrane (OM) of P. gingivalis cells and secreted into the extracellular milieu, where it is detected in a soluble form and in association with outer membrane vesicles (OMVs)...
June 12, 2018: Scientific Reports
Dylan W White, Sarah R Elliott, Evan Odean, Lynne T Bemis, Anna D Tischler
Mycobacterium tuberculosis releases membrane vesicles (MV) that modulate host immune responses and aid in iron acquisition, although they may have additional unappreciated functions. MV production appears to be a regulated process, but virR remains the only characterized genetic regulator of vesiculogenesis. Here, we present data supporting a role for the M. tuberculosis Pst/SenX3-RegX3 signal transduction system in regulating MV production. Deletion of pstA1 , which encodes a transmembrane component of the phosphate-specific transport (Pst) system, causes constitutive activation of the SenX3-RegX3 two-component system, leading to increased protein secretion via the specialized ESX-5 type VII secretion system...
June 12, 2018: MBio
Xin-Hong Dong, Meng-Hsuan Ho, Bindong Liu, James Hildreth, Chandravanu Dash, J Shawn Goodwin, Muthukumar Balasubramaniam, Chin-Ho Chen, Hua Xie
The association between mucosal microbiota and HIV-1 infection has garnered great attention in the field of HIV-1 research. Previously, we reported a receptor-independent HIV-1 entry into epithelial cells mediated by a Gram-negative invasive bacterium, Porphyromonas gingivalis. Here, we present evidence showing that P. gingivalis outer membrane vesicles (OMVs) promote mucosal transmission of HIV-1. We demonstrated, using the Dynabeads technology, a specific interaction between HIV-1 and P. gingivalis OMVs which led to an OMV-dependent viral entry into oral epithelial cells...
June 11, 2018: Scientific Reports
Danielle L Kopke, Kendal Broadie
FM dyes are used to study the synaptic vesicle (SV) cycle. These amphipathic probes have a hydrophilic head and hydrophobic tail, making them water-soluble with the ability to reversibly enter and exit membrane lipid bilayers. These styryl dyes are relatively non-fluorescent in aqueous medium, but insertion into the outer leaflet of the plasma membrane causes a >40X increase in fluorescence. In neuronal synapses, FM dyes are internalized during SV endocytosis, trafficked both within and between SV pools, and released with SV exocytosis, providing a powerful tool to visualize presynaptic stages of neurotransmission...
May 24, 2018: Journal of Visualized Experiments: JoVE
Adriana B Cesari, Natalia S Paulucci, María A Biasutti, Gustavo M Morales, Marta S Dardanelli
We evaluate the behavior of the membrane of Bradyrhizobium sp. SEMIA6144 during adaptation to polyethylene glycol (PEG). A dehydrating effect on the morphology of the cell surface, as well as a fluidizing effect on the membrane was observed 10 min after PEG shock; however, the bacteria were able to restore optimal membrane fluidity. Shock for 1 h caused an increase of lysophosphatidylethanolamine in the outer membrane at the expense of phosphatidylcholine and phosphatidylethanolamine, through an increase in phospholipase activity...
June 1, 2018: Research in Microbiology
Anjali Malge, Vikas Ghai, Panga Jaipal Reddy, David Baxter, Taek-Kyun Kim, Robert L Moritz, Kai Wang
Borrelia burgdorferi, a bacterium in the spirochete phylum, is the causative agent of Lyme disease. B. burgdorferi has a linear chromosome with a number of circular and linear plasmids. Bacteria, including B. burgdorferi, release spherical outer membrane vesicles (OMVs) that are known to carry secretory products including metabolites, nucleic acids and proteins. Herein, we provide the first comparative transcriptomic analysis of the vesicles released from B. burgdorferi. We identified a total of ∼1200 unique transcripts with at least one mapped read from the bacterial cell and its OMVs...
May 28, 2018: FEMS Microbiology Letters
Paula Martins, Daisy Machado, Thais Holtz Theizen, João Paulo Oliveira Guarnieri, Bruno Gaia Bernardes, Gabriel Piccirillo Gomide, Marcus Alexandre Finzi Corat, Camilla Abbehausen, José Luiz Proença Módena, Carlos Fernando Odir Rodrigues Melo, Karen Noda Morishita, Rodrigo Ramos Catharino, Clarice Weis Arns, Marcelo Lancellotti
The increase of Zika virus (ZIKV) infections in Brazil in the last two years leaves a prophylactic measures on alert for this new and emerging pathogen. Concerning of our positive experience, we developed a new prototype using Neisseria meningitidis outer membrane vesicles (OMV) on ZIKV cell growth in a fusion of OMV in the envelope of virus particles. The fusion of nanoparticles resulting from outer membrane vesicles of N. meningitidis with infected C6/36 cells line were analyzed by Nano tracking analysis (NTA), zeta potential, differential light scattering (DLS), scan and scanning transmission eletronic microscopy (SEM and STEM) and high resolution mass spectometry (HRMS) for nanostructure characterization...
May 29, 2018: Scientific Reports
Keel Yong Lee, Sung-Jin Park, Keon Ah Lee, Se-Hwan Kim, Heeyeon Kim, Yasmine Meroz, L Mahadevan, Kwang-Hwan Jung, Tae Kyu Ahn, Kevin Kit Parker, Kwanwoo Shin
Inside cells, complex metabolic reactions are distributed across the modular compartments of organelles. Reactions in organelles have been recapitulated in vitro by reconstituting functional protein machineries into membrane systems. However, maintaining and controlling these reactions is challenging. Here we designed, built, and tested a switchable, light-harvesting organelle that provides both a sustainable energy source and a means of directing intravesicular reactions. An ATP (ATP) synthase and two photoconverters (plant-derived photosystem II and bacteria-derived proteorhodopsin) enable ATP synthesis...
May 28, 2018: Nature Biotechnology
Gakushi Tsuji, Takeshi Sunami, Norikazu Ichihashi
Giant unilamellar vesicles (GUVs) are large vesicles bounded by a single lipid bilayer, which have been used in various applications as artificial, cell-like compartments. The water-in-oil (w/o) emulsion-transfer method has been attracting attention as a method to prepare GUVs that can efficiently encapsulate macromolecules. For efficient GUV production by this method, non-physiological, high concentrations of sugars are usually required in the inner solution of the GUVs. These sugars limit the utility of the GUVs for a wide range of applications...
May 21, 2018: Journal of Bioscience and Bioengineering
Rassoul Hashemzehi, Abbas Doosti, Mohammad Kargar, Mojtaba Jaafarinia
Acinetobacter baumannii is one of the highly antibiotic-resistant bacteria that cause infections with high rate of death. This bacterium is one the common causes of infection worldwide leading to endemic and epidemic nosocomial infections. Despite many efforts, there is no effective vaccine against A. baumannii. As NlpA is one of the important antigenic factors in biogenesis of outer membrane vesicles, and OMV-based reported vaccines in A. baumannii stimulated the immune responses, this study was aimed to clone and express nlpA gene in eukaryotic HDF cells and evaluate the induced immunization following the administration of resulting construct as DNA vaccine in BALB/c mice...
May 22, 2018: Molecular Biology Reports
Babak Beikzadeh, Gholamreza Nikbakht Brujeni
OBJECTIVE: Enterotoxigenic Escherichia Coli (ETEC) is the cause of diarrhea and even death in humans and offspring of animals. Outer membrane vesicles (OMVs) of the ETEC was prepared and its potential as a vaccine candidate against enteric colibacillosis in neonatal mice was evaluated. Dam mice intradermally injected with ETEC-derived OMVs and OMVs plus an active form of vitamin D3 (avD3). Mucosal and systemic immune responses in mice and passive immunity protection against ETEC lethality in their offspring was investigated...
May 16, 2018: BMC Research Notes
Clement Chan, Vahid F Andisi, Dixon Ng, Nick Ostan, Warren K Yunker, Anthony B Schryvers
A number of important Gram-negative pathogens that reside exclusively in the upper respiratory or genitourinary tract of their mammalian host rely on surface receptors that specifically bind host transferrin and lactoferrin as a source of iron for growth. The transferrin receptors have been targeted for vaccine development due to their critical role in acquiring iron during invasive infection and for survival on the mucosal surface. In this study, we focus on the lactoferrin receptors, determining their prevalence in pathogenic bacteria and comparing their prevalence in commensal Neisseria to other surface antigens targeted for vaccines; addressing the issue of a reservoir for vaccine escape and impact of vaccination on the microbiome...
May 16, 2018: Biometals: An International Journal on the Role of Metal Ions in Biology, Biochemistry, and Medicine
Paul D Veith, Caroline Luong, Keng H Tan, Stuart G Dashper, Eric C Reynolds
Porphyromonas gingivalis is an anaerobic, Gram-negative oral pathogen associated with chronic periodontitis. P. gingivalis has an obligate requirement for heme which it obtains from the host. Heme availability has been linked to disease initiation and progression. In this study we used continuous culture of the bacterium to determine the effect of heme limitation and excess on the P. gingivalis proteome. Four biological replicates of whole cell lysate (WCL) and outer membrane vesicle (OMV) samples were digested with trypsin and analysed by tandem mass spectrometry and MaxQuant label-free quantification...
May 16, 2018: Journal of Proteome Research
Michael P Hays, Diane Houben, Yang Yang, Joen Luirink, Philip R Hardwidge
Outer membrane vesicles (OMVs) are promising vaccine components because they combine antigen and adjuvant in a single formulation. Detoxified Salmonella enterica strains that express penta-acylated lipid A retain OMV immunogenicity but with reduced reactogenicity. We have previously shown that a recombinant form of the enterotoxigenic Escherichia coli (ETEC) 17 kilodalton protein (Skp) protects mice in a pulmonary challenge model, when fused to the glutathione-S-transferase (GST) epitope and combined with cholera toxin...
2018: Frontiers in Cellular and Infection Microbiology
Kuang Tan, Ruizhen Li, Xiaotian Huang, Qiong Liu
Adjuvants have been of great interest to vaccine formulation as immune-stimulators. Prior to the recent research in the field of immune stimulation, conventional adjuvants utilized for aluminum-based vaccinations dominated the adjuvant market. However, these conventional adjuvants have demonstrated obvious defects, including poor protective efficiency and potential side effects, which hindered their widespread circulation. Outer membrane vesicles (OMVs) naturally exist in gram-negative bacteria and are capable of engaging innate and adaptive immunity and possess intrinsic adjuvant capacity...
2018: Frontiers in Microbiology
Weiyan Zhu, Joshua Tomberg, Kayla J Knilans, James E Anderson, Karen P McKinnon, Gregory D Sempowski, Robert A Nicholas, Joseph A Duncan
Neisseria gonorrhoeae is an exclusive human pathogen that evades the host immune system through multiple mechanisms. We have shown that N. gonorrhoeae  suppresses the capacity of antigen-presenting cells to induce CD4+ T cell proliferation. In this study, we sought to determine the gonococcal factors involved in this adaptive immune suppression. We show that suppression of the capacity of antigen-pulsed dendritic cells to induce T cell proliferation is recapitulated by administration of a high molecular weight fraction of conditioned medium from N...
May 11, 2018: Journal of Biological Chemistry
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