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Prince A, Tiwari A, Mandal T, Koiri D, Meher G, Sinha DK, Saleem M. Lipid Specificity of the Fusion of Bacterial Extracellular Vesicles with the Host Membrane. J Phys Chem B 2024. [PMID: 38981091 DOI: 10.1021/acs.jpcb.4c02321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2024]
Abstract
Bacterial membrane vesicles (MVs) facilitate the long-distance delivery of virulence factors crucial for pathogenicity. The entry and trafficking mechanisms of virulence factors inside host cells are recently emerging; however, whether bacterial MVs can fuse and modulate the physicochemical properties of the host lipid membrane and membrane lipid parameter for fusion remains unknown. In this study, we reconstituted the interaction of bacterial MVs with host cell lipid membranes and quantitatively showed that bacterial MV interaction increases the fluidity, dipole potential, and compressibility of a biologically relevant multicomponent host membrane upon fusion. The presence of cylindrical lipids, such as phosphatidylcholine, and a moderate acyl chain length of C16 help the MV interaction. While significant binding of bacterial MVs to the raft-like lipid membranes with phase-separated regions of the membrane was observed, however, MVs prefer binding to the liquid-disordered regions of the membrane. Furthermore, the elevated levels of cholesterol tend to hinder the interaction of bacterial MVs, as evident from the favorable excess Gibbs free energy of mixing bacterial MVs with host lipid membranes. The findings provide new insights that might have implications for the regulation of host machinery by bacterial pathogens through manipulation of the host membrane properties.
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Affiliation(s)
- Ashutosh Prince
- Department of Life Sciences, National Institute of Technology, Rourkela 769008, India
| | - Anuj Tiwari
- Department of Life Sciences, National Institute of Technology, Rourkela 769008, India
| | - Titas Mandal
- Department of Physical Biochemistry, University of Potsdam, Potsdam 14476, Germany
| | - Debraj Koiri
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India
- Homi Bhabha National Institute, Mumbai 400094, India
| | - Geetanjali Meher
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India
- Homi Bhabha National Institute, Mumbai 400094, India
| | - Deepak Kumar Sinha
- Department of Biological Chemistry, Indian Association for the Cultivation of Sciences, Kolkata 700032, India
| | - Mohammed Saleem
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India
- Homi Bhabha National Institute, Mumbai 400094, India
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2
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Bardy P, MacDonald CI, Kirchberger PC, Jenkins HT, Botka T, Byrom L, Alim NT, Traore DA, König HC, Nicholas TR, Chechik M, Hart SJ, Turkenburg JP, Blaza JN, Beatty JT, Fogg PC, Antson AA. A stargate mechanism of Microviridae genome delivery unveiled by cryogenic electron tomography. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.11.598214. [PMID: 38915634 PMCID: PMC11195240 DOI: 10.1101/2024.06.11.598214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Single-stranded DNA bacteriophages of the Microviridae family are major components of the global virosphere. Microviruses are highly abundant in aquatic ecosystems and are prominent members of the mammalian gut microbiome, where their diversity has been linked to various chronic health disorders. Despite the clear importance of microviruses, little is known about the molecular mechanism of host infection. Here, we have characterized an exceptionally large microvirus, Ebor, and provide crucial insights into long-standing mechanistic questions. Cryogenic electron microscopy of Ebor revealed a capsid with trimeric protrusions that recognise lipopolysaccharides on the host surface. Cryogenic electron tomography of the host cell colonized with virus particles demonstrated that the virus initially attaches to the cell via five such protrusions, located at the corners of a single pentamer. This interaction triggers a stargate mechanism of capsid opening along the 5-fold symmetry axis, enabling delivery of the virus genome. Despite variations in specific virus-host interactions among different Microviridae family viruses, structural data indicate that the stargate mechanism of infection is universally employed by all members of the family. Startlingly, our data reveal a mechanistic link for the opening of relatively small capsids made out of a single jelly-roll fold with the structurally unrelated giant viruses.
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Affiliation(s)
- Pavol Bardy
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
- York Biomedical Research Institute, University of York, York, United Kingdom. YO10 5NG
| | - Conor I.W. MacDonald
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
| | - Paul C. Kirchberger
- Department of Microbiology & Molecular Genetics, Oklahoma State University, US
| | - Huw T. Jenkins
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
- York Biomedical Research Institute, University of York, York, United Kingdom. YO10 5NG
| | - Tibor Botka
- Department of Experimental Biology, Faculty of Science, Masaryk University, 625 00, Brno, Czech Republic
| | - Lewis Byrom
- York Biomedical Research Institute, University of York, York, United Kingdom. YO10 5NG
- Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Nawshin T.B. Alim
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, V6T 1Z3, BC, Canada
| | - Daouda A.K. Traore
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG, Eindhoven, The Netherlands
| | - Hannah C. König
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, V6T 1Z3, BC, Canada
| | - Tristan R. Nicholas
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
- York Biomedical Research Institute, University of York, York, United Kingdom. YO10 5NG
| | - Maria Chechik
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
- York Biomedical Research Institute, University of York, York, United Kingdom. YO10 5NG
| | - Samuel J. Hart
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
| | - Johan P. Turkenburg
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
| | - James N. Blaza
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
- York Biomedical Research Institute, University of York, York, United Kingdom. YO10 5NG
| | - J. Thomas Beatty
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, V6T 1Z3, BC, Canada
| | - Paul C.M. Fogg
- York Biomedical Research Institute, University of York, York, United Kingdom. YO10 5NG
- Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Alfred A. Antson
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
- York Biomedical Research Institute, University of York, York, United Kingdom. YO10 5NG
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3
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Saci S, Msela A, Saoudi B, Sebbane H, Trabelsi L, Alam M, Ernst B, Benguerba Y, Houali K. Assessment of antibacterial activity, modes of action, and synergistic effects of Origanum vulgare hydroethanolic extract with antibiotics against avian pathogenic Escherichia coli. Fitoterapia 2024; 177:106055. [PMID: 38838822 DOI: 10.1016/j.fitote.2024.106055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Revised: 05/28/2024] [Accepted: 06/01/2024] [Indexed: 06/07/2024]
Abstract
This study evaluates the antibacterial effectiveness of Origanum vulgare hydroethanolic extract, both independently and in combination with antibiotics, against Escherichia coli strains associated with avian colibacillosis-a significant concern for the poultry industry due to the rise of antibiotic-resistant E. coli. The urgent demand for new treatments is addressed by analyzing the extract's phytochemical makeup via High-Performance Liquid Chromatography (HPLC), which identified sixteen phenolic compounds. Antibacterial activity was determined through agar diffusion and the measurement of minimum inhibitory and bactericidal concentrations (MIC and MBC), showing moderate efficacy (MIC: 3.9 to 7.8 mg/mL, MBC: 31.2 to 62.4 mg/mL). Combining the extract with antibiotics like ampicillin and tetracycline amplified antibacterial activity, indicating a synergistic effect and highlighting the importance of combinatory treatments against resistant strains. Further analysis revealed the extract's mechanisms of action include disrupting bacterial cell membrane integrity and inhibiting ATPase/H+ proton pumps, essential for bacterial survival. Moreover, the extract effectively inhibited and eradicated biofilms, crucial for preventing bacterial colonization. Regarding cytotoxicity, the extract showed no hemolytic effect at 1 to 9 mg/mL concentrations. These results suggest Origanum vulgare extract, particularly when used with antibiotics, offers a promising strategy for managing avian colibacillosis, providing both direct antibacterial benefits and moderating antibiotic resistance, thus potentially reducing the economic impact of the disease on the poultry industry.
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Affiliation(s)
- Sarah Saci
- Laboratoire de Biochimie Analytique et Biotechnologies (LABAB), Faculté des Sciences Biologiques et Agronomiques, Université Mouloud MAMMERI de Tizi-Ouzou, Algeria
| | - Amine Msela
- Laboratoire de Biochimie Analytique et Biotechnologies (LABAB), Faculté des Sciences Biologiques et Agronomiques, Université Mouloud MAMMERI de Tizi-Ouzou, Algeria
| | - Bilal Saoudi
- Laboratoire de Biochimie Analytique et Biotechnologies (LABAB), Faculté des Sciences Biologiques et Agronomiques, Université Mouloud MAMMERI de Tizi-Ouzou, Algeria
| | - Hillal Sebbane
- Laboratoire de Biochimie Analytique et Biotechnologies (LABAB), Faculté des Sciences Biologiques et Agronomiques, Université Mouloud MAMMERI de Tizi-Ouzou, Algeria
| | - Lamia Trabelsi
- Marine Biodiversity Laboratory, National Institute of Marine Sciences and Technology (inStm), University of Carthage, Tunis, Tunisia
| | - Manawwer Alam
- Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Barbara Ernst
- Université de Strasbourg, CNRS, IPHC UMR 7178, Laboratoire de Reconnaissance et Procédés de Séparation Moléculaire (RePSeM), ECPM 25 rue Becquerel, F-67000 Strasbourg, France
| | - Yacine Benguerba
- Laboratoire de Biopharmacie Et Pharmacotechnie (LBPT), Université Ferhat ABBAS Sétif-1, Sétif, Algeria.
| | - Karim Houali
- Laboratoire de Biochimie Analytique et Biotechnologies (LABAB), Faculté des Sciences Biologiques et Agronomiques, Université Mouloud MAMMERI de Tizi-Ouzou, Algeria.
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Gontijo M, Pereira Teles M, Martins Correia H, Pérez Jorge G, Rodrigues Santos Goes IC, Fasabi Flores AJ, Braz M, de Moraes Ceseti L, Zonzini Ramos P, Rosa e Silva I, Pereira Vidigal PM, Kobarg J, Miguez Couñago R, Alvarez-Martinez CE, Pereira C, Freire CSR, Almeida A, Brocchi M. Combined effect of SAR-endolysin LysKpV475 with polymyxin B and Salmonella bacteriophage phSE-5. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001462. [PMID: 38739436 PMCID: PMC11170124 DOI: 10.1099/mic.0.001462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 04/26/2024] [Indexed: 05/14/2024]
Abstract
Endolysins are bacteriophage (or phage)-encoded enzymes that catalyse the peptidoglycan breakdown in the bacterial cell wall. The exogenous action of recombinant phage endolysins against Gram-positive organisms has been extensively studied. However, the outer membrane acts as a physical barrier when considering the use of recombinant endolysins to combat Gram-negative bacteria. This study aimed to evaluate the antimicrobial activity of the SAR-endolysin LysKpV475 against Gram-negative bacteria as single or combined therapies, using an outer membrane permeabilizer (polymyxin B) and a phage, free or immobilized in a pullulan matrix. In the first step, the endolysin LysKpV475 in solution, alone and combined with polymyxin B, was tested in vitro and in vivo against ten Gram-negative bacteria, including highly virulent strains and multidrug-resistant isolates. In the second step, the lyophilized LysKpV475 endolysin was combined with the phage phSE-5 and investigated, free or immobilized in a pullulan matrix, against Salmonella enterica subsp. enterica serovar Typhimurium ATCC 13311. The bacteriostatic action of purified LysKpV475 varied between 8.125 μg ml-1 against Pseudomonas aeruginosa ATCC 27853, 16.25 μg ml-1 against S. enterica Typhimurium ATCC 13311, and 32.50 μg ml-1 against Klebsiella pneumoniae ATCC BAA-2146 and Enterobacter cloacae P2224. LysKpV475 showed bactericidal activity only for P. aeruginosa ATCC 27853 (32.50 μg ml-1) and P. aeruginosa P2307 (65.00 μg ml-1) at the tested concentrations. The effect of the LysKpV475 combined with polymyxin B increased against K. pneumoniae ATCC BAA-2146 [fractional inhibitory concentration index (FICI) 0.34; a value lower than 1.0 indicates an additive/combined effect] and S. enterica Typhimurium ATCC 13311 (FICI 0.93). A synergistic effect against S. enterica Typhimurium was also observed when the lyophilized LysKpV475 at ⅔ MIC was combined with the phage phSE-5 (m.o.i. of 100). The lyophilized LysKpV475 immobilized in a pullulan matrix maintained a significant Salmonella reduction of 2 logs after 6 h of treatment. These results demonstrate the potential of SAR-endolysins, alone or in combination with other treatments, in the free form or immobilized in solid matrices, which paves the way for their application in different areas, such as in biocontrol at the food processing stage, biosanitation of food contact surfaces and biopreservation of processed food in active food packing.
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Affiliation(s)
- Marco Gontijo
- Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP 13083-862, Brazil
| | - Mateus Pereira Teles
- Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP 13083-862, Brazil
- Laboratório Nacional de Biociências (LNBio), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, SP 13083-970, Brazil
- Department of Biology, and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal
| | - Hugo Martins Correia
- Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP 13083-862, Brazil
| | - Genesy Pérez Jorge
- Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP 13083-862, Brazil
- Research Group Statistics and Mathematical Modeling Applied to Educational Quality (GEMMA), University of Sucre, Sincelejo, Sucre, Colombia
| | - Isabella Carolina Rodrigues Santos Goes
- Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP 13083-862, Brazil
| | - Anthony Jhoao Fasabi Flores
- Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP 13083-862, Brazil
| | - Márcia Braz
- Department of Biology, and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal
| | - Lucas de Moraes Ceseti
- Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP 13083-862, Brazil
| | - Priscila Zonzini Ramos
- Centro de Química Medicinal, Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas (UNICAMP), Campinas, SP 13083-970, Brazil
| | - Ivan Rosa e Silva
- Laboratório Nacional de Biociências (LNBio), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, SP 13083-970, Brazil
- Faculdade de Ciências Farmacêuticas, Universidade Estadual de Campinas (UNICAMP), Campinas, SP 13083-871, Brazil
| | - Pedro Marcus Pereira Vidigal
- Núcleo de Análise de Biomoléculas (NuBioMol), Universidade Federal de Viçosa (UFV), Viçosa, MG 36570-900, Brazil
| | - Jörg Kobarg
- Faculdade de Ciências Farmacêuticas, Universidade Estadual de Campinas (UNICAMP), Campinas, SP 13083-871, Brazil
| | - Rafael Miguez Couñago
- Centro de Química Medicinal, Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas (UNICAMP), Campinas, SP 13083-970, Brazil
| | - Cristina Elisa Alvarez-Martinez
- Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP 13083-862, Brazil
| | - Carla Pereira
- Department of Biology, and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal
| | - Carmen S. R. Freire
- CICECO – Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Adelaide Almeida
- Department of Biology, and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal
| | - Marcelo Brocchi
- Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP 13083-862, Brazil
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Cingolani G, Lokareddy R, Hou CF, Forti F, Iglesias S, Li F, Pavlenok M, Niederweis M, Briani F. Integrative structural analysis of Pseudomonas phage DEV reveals a genome ejection motor. RESEARCH SQUARE 2024:rs.3.rs-3941185. [PMID: 38463957 PMCID: PMC10925440 DOI: 10.21203/rs.3.rs-3941185/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
DEV is an obligatory lytic Pseudomonas phage of the N4-like genus, recently reclassified as Schitoviridae. The DEV genome encodes 91 ORFs, including a 3,398 amino acid virion-associated RNA polymerase. Here, we describe the complete architecture of DEV, determined using a combination of cryo-electron microscopy localized reconstruction, biochemical methods, and genetic knockouts. We built de novo structures of all capsid factors and tail components involved in host attachment. We demonstrate that DEV long tail fibers are essential for infection of Pseudomonas aeruginosa and dispensable for infecting mutants with a truncated lipopolysaccharide devoid of the O-antigen. We identified DEV ejection proteins and, unexpectedly, found that the giant DEV RNA polymerase, the hallmark of the Schitoviridae family, is an ejection protein. We propose that DEV ejection proteins form a genome ejection motor across the host cell envelope and that these structural principles are conserved in all Schitoviridae.
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Dediu Botezatu AV, Apetrei RM, Costea Nour IF, Barbu V, Grigore-Gurgu L, Botez F, Dinica RM, Furdui B, Cârâc G. Synthesis and characterization of novel chitosan derivatives (containing dipyridinium quaternary salts) with antimicrobial potential. Carbohydr Res 2023; 534:108964. [PMID: 37925873 DOI: 10.1016/j.carres.2023.108964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 09/26/2023] [Accepted: 10/02/2023] [Indexed: 11/07/2023]
Abstract
Chitosan derivatives are versatile materials, biocompatible and biodegradable, that can be tailor-made to suit specific biomedical applications. In this study, two N-heterocyclic salts (N,N'-diphenacyl-[4,4'-dipyridinium] dibromide (DP) and N,N'-diphenacyl-1,2-bis-(4-pyridinium)ethane dibromide (DPE)) were used for chitosan functionalization to enhance its antimicrobial potential. Physico-chemical characterization of the newly synthesized derivatives (Ch-DP and Ch-DPE) was performed by elemental analysis, spectrometry (UV-Vis, FTIR), electrochemistry (OCP, CV), and electron microscopy (SEM) proving that the highest degree of functionalization was obtained for Ch-DP. The antimicrobial effect of chitosan functionalization was further tested in terms of its interaction with Listeria monocytogenes Scott A, and Staphylococcus aureus ATCC 25923, as Gram-positive bacteria and Escherichia coli ATCC 25922, as Gram-negative bacterium, respectively, showing that the Ch-DP had a good inhibitory activity compared with Ch-DPE.
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Affiliation(s)
- Andreea Veronica Dediu Botezatu
- (")Dunarea de Jos" University of Galati, Faculty of Science and Environment, Department of Chemistry, Physics and Environment, Domneasca Street 111, 800201, Galati, Romania.
| | - Roxana-Mihaela Apetrei
- (")Dunarea de Jos" University of Galati, Faculty of Science and Environment, Department of Chemistry, Physics and Environment, Domneasca Street 111, 800201, Galati, Romania; "Dunarea de Jos" University of Galai, Rexdan Research Infrastructure, George Coșbuc Bdv. 98, 800385, Galati, Romania.
| | - Iuliana Florina Costea Nour
- (")Dunarea de Jos" University of Galati, Faculty of Science and Environment, Department of Chemistry, Physics and Environment, Domneasca Street 111, 800201, Galati, Romania.
| | - Vasilica Barbu
- ('')Dunarea de Jos" University of Galati, Faculty of Food Science and Engineering, Domneasca Street 111, 800201, Galati, Romania.
| | - Leontina Grigore-Gurgu
- ('')Dunarea de Jos" University of Galati, Faculty of Food Science and Engineering, Domneasca Street 111, 800201, Galati, Romania.
| | - Florina Botez
- University of Bucharest, Faculty of Biology, Department of Systems Ecology, Splaiul Independenţei no. 91-95, District 5, 050095, Bucharest, Romania.
| | - Rodica Mihaela Dinica
- (")Dunarea de Jos" University of Galati, Faculty of Science and Environment, Department of Chemistry, Physics and Environment, Domneasca Street 111, 800201, Galati, Romania.
| | - Bianca Furdui
- (")Dunarea de Jos" University of Galati, Faculty of Science and Environment, Department of Chemistry, Physics and Environment, Domneasca Street 111, 800201, Galati, Romania.
| | - Geta Cârâc
- (")Dunarea de Jos" University of Galati, Faculty of Science and Environment, Department of Chemistry, Physics and Environment, Domneasca Street 111, 800201, Galati, Romania.
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7
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Nair KS, Bajaj H. Advances in giant unilamellar vesicle preparation techniques and applications. Adv Colloid Interface Sci 2023; 318:102935. [PMID: 37320960 DOI: 10.1016/j.cis.2023.102935] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 05/23/2023] [Accepted: 06/05/2023] [Indexed: 06/17/2023]
Abstract
Giant unilamellar vesicles (GUVs) are versatile and promising cell-sized bio-membrane mimetic platforms. Their applications range from understanding and quantifying membrane biophysical processes to acting as elementary blocks in the bottom-up assembly of synthetic cells. Definite properties and requisite goals in GUVs are dictated by the preparation techniques critical to the success of their applications. Here, we review key advances in giant unilamellar vesicle preparation techniques and discuss their formation mechanisms. Developments in lipid hydration and emulsion techniques for GUV preparation are described. Novel microfluidic-based techniques involving lipid or surfactant-stabilized emulsions are outlined. GUV immobilization strategies are summarized, including gravity-based settling, covalent linking, and immobilization by microfluidic, electric, and magnetic barriers. Moreover, some of the key applications of GUVs as biomimetic and synthetic cell platforms during the last decade have been identified. Membrane interface processes like phase separation, membrane protein reconstitution, and membrane bending have been deciphered using GUVs. In addition, vesicles are also employed as building blocks to construct synthetic cells with defined cell-like functions comprising compartments, metabolic reactors, and abilities to grow and divide. We critically discuss the pros and cons of preparation technologies and the properties they confer to the GUVs and identify potential techniques for dedicated applications.
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Affiliation(s)
- Karthika S Nair
- Microbial Processes and Technology Division, CSIR- National Institute for Interdisciplinary Science and Technology (NIIST), Trivandrum 695019, Kerala, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-Human Resource Development Centre, Ghaziabad 201002, India
| | - Harsha Bajaj
- Microbial Processes and Technology Division, CSIR- National Institute for Interdisciplinary Science and Technology (NIIST), Trivandrum 695019, Kerala, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-Human Resource Development Centre, Ghaziabad 201002, India.
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8
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Kang J, Mateu-Borrás M, Monroe HL, Sen-Kilic E, Miller SJ, Dublin SR, Huckaby AB, Yang E, Pyles GM, Nunley MA, Chapman JA, Amin MS, Damron FH, Barbier M. Monoclonal antibodies against lipopolysaccharide protect against Pseudomonas aeruginosa challenge in mice. Front Cell Infect Microbiol 2023; 13:1191806. [PMID: 37424774 PMCID: PMC10326049 DOI: 10.3389/fcimb.2023.1191806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 06/09/2023] [Indexed: 07/11/2023] Open
Abstract
Pseudomonas aeruginosa is a common cause of hospital-acquired infections, including central line-associated bloodstream infections and ventilator-associated pneumonia. Unfortunately, effective control of these infections can be difficult, in part due to the prevalence of multi-drug resistant strains of P. aeruginosa. There remains a need for novel therapeutic interventions against P. aeruginosa, and the use of monoclonal antibodies (mAb) is a promising alternative strategy to current standard of care treatments such as antibiotics. To develop mAbs against P. aeruginosa, we utilized ammonium metavanadate, which induces cell envelope stress responses and upregulates polysaccharide expression. Mice were immunized with P. aeruginosa grown with ammonium metavanadate and we developed two IgG2b mAbs, WVDC-0357 and WVDC-0496, directed against the O-antigen lipopolysaccharide of P. aeruginosa. Functional assays revealed that WVDC-0357 and WVDC-0496 directly reduced the viability of P. aeruginosa and mediated bacterial agglutination. In a lethal sepsis model of infection, prophylactic treatment of mice with WVDC-0357 and WVDC-0496 at doses as low as 15 mg/kg conferred 100% survival against challenge. In both sepsis and acute pneumonia models of infection, treatment with WVDC-0357 and WVDC-0496 significantly reduced bacterial burden and inflammatory cytokine production post-challenge. Furthermore, histopathological examination of the lungs revealed that WVDC-0357 and WVDC-0496 reduced inflammatory cell infiltration. Overall, our results indicate that mAbs directed against lipopolysaccharide are a promising therapy for the treatment and prevention of P. aeruginosa infections.
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Affiliation(s)
- Jason Kang
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, WV, United States
- Vaccine Development Center, West Virginia University Health Sciences Center, Morgantown, WV, United States
| | - Margalida Mateu-Borrás
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, WV, United States
- Vaccine Development Center, West Virginia University Health Sciences Center, Morgantown, WV, United States
| | - Hunter L. Monroe
- Department of Pathology, Anatomy, and Laboratory Medicine, West Virginia University, Morgantown, WV, United States
| | - Emel Sen-Kilic
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, WV, United States
- Vaccine Development Center, West Virginia University Health Sciences Center, Morgantown, WV, United States
| | - Sarah Jo Miller
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, WV, United States
- Vaccine Development Center, West Virginia University Health Sciences Center, Morgantown, WV, United States
| | - Spencer R. Dublin
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, WV, United States
- Vaccine Development Center, West Virginia University Health Sciences Center, Morgantown, WV, United States
| | - Annalisa B. Huckaby
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, WV, United States
- Vaccine Development Center, West Virginia University Health Sciences Center, Morgantown, WV, United States
| | - Evita Yang
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, WV, United States
- Vaccine Development Center, West Virginia University Health Sciences Center, Morgantown, WV, United States
| | - Gage M. Pyles
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, WV, United States
- Vaccine Development Center, West Virginia University Health Sciences Center, Morgantown, WV, United States
| | - Mason A. Nunley
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, WV, United States
- Vaccine Development Center, West Virginia University Health Sciences Center, Morgantown, WV, United States
| | - Josh A. Chapman
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, WV, United States
- Vaccine Development Center, West Virginia University Health Sciences Center, Morgantown, WV, United States
| | - Md Shahrier Amin
- Department of Pathology, Anatomy, and Laboratory Medicine, West Virginia University, Morgantown, WV, United States
| | - F. Heath Damron
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, WV, United States
- Vaccine Development Center, West Virginia University Health Sciences Center, Morgantown, WV, United States
| | - Mariette Barbier
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, WV, United States
- Vaccine Development Center, West Virginia University Health Sciences Center, Morgantown, WV, United States
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9
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Leonida MD, Benzecry A, Lozanovska B, Mahmoud Z, Reid A, Belbekhouche S. Impact of tannic acid on nisin encapsulation in chitosan particles. Int J Biol Macromol 2023; 233:123489. [PMID: 36736978 DOI: 10.1016/j.ijbiomac.2023.123489] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 01/25/2023] [Accepted: 01/27/2023] [Indexed: 02/05/2023]
Abstract
This study investigates the effect of addition of tannic acid on nisin encapsulated in chitosan matrices. Composite materials were prepared using a mild, environmentally friendly procedure, ionotropic gelation of chitosan by sodium tripolyphosphate in the presence of nisin (N) at different concentrations. In two parallel sets of preparations, tannic acid (TA) was added at 10:1 and 5:1 N:TA, respectively. The obtained particles were characterized by FTIR, SEM, size, zeta potential, encapsulation efficiency, loading capacity, and ratio of residual free amino groups. The kinetics of nisin release from the particles was studied to assess the role of TA as a potential modulator thereof. Its addition resulted in enhanced release, higher at lower N:TA ratio. An additional benefit was that TA, a strong antioxidant, imparted antioxidant activity to the composites. Antimicrobial turbidimetric tests were performed against one gram-positive bacterium (Staphylococcus aureus) and two gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), all relevant for the food, pharmaceutical, and cosmetic industries. All the composites showed synergistic effects against all the bacteria tested. The positive coaction was stronger against the gram-negative species. This is remarkable since nisin by itself has not known activity against them.
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Affiliation(s)
- Mihaela D Leonida
- Department of Chemistry and Biochemistry, Fairleigh Dickinson University, Teaneck, NJ 07666, USA.
| | - Alice Benzecry
- Department of Chemistry and Biochemistry, Fairleigh Dickinson University, Teaneck, NJ 07666, USA
| | - Bisera Lozanovska
- Department of Chemistry and Biochemistry, Fairleigh Dickinson University, Teaneck, NJ 07666, USA
| | - Zainab Mahmoud
- Department of Chemistry and Biochemistry, Fairleigh Dickinson University, Teaneck, NJ 07666, USA
| | - Ashley Reid
- Department of Chemistry and Biochemistry, Fairleigh Dickinson University, Teaneck, NJ 07666, USA
| | - Sabrina Belbekhouche
- Université Paris Est Créteil, CNRS, Institut Chimie et Matériaux Paris Est, UMR 7182, 2 Rue Henri Dunant, 94320 Thiais, France.
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10
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He N, Zhao T. Propranolol induces large-scale remodeling of lipid bilayers: tubules, patches, and holes. RSC Adv 2023; 13:7719-7730. [PMID: 36908547 PMCID: PMC9994463 DOI: 10.1039/d3ra00319a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 03/01/2023] [Indexed: 03/11/2023] Open
Abstract
Herein, we report fluorescence microscopy analysis of the interaction between propranolol (PPN), a beta-adrenergic blocking agent, and planar supported lipid bilayers (SLBs), as model membranes. The results indicate that PPN can remarkably promote largescale remodeling in SLBs with various lipid compositions. It was found that PPN insertion induces the formation of long microtubules that can retract into hemispherical caps on the surface of the bilayer. These transformations are dynamic, partially reversible, and dependent upon the drug concentration. Quantitative analysis revealed a three-step model for PPN-lipid bilayer interaction, with the first step involving interfacial electrostatic adsorption, the second step centered on hydrophobic insertion, and the third step associated with membrane disruption and hole formation. By introducing cholesterol, phosphoethanolamine, phosphatidylglycerol, and phosphatidylserine lipids into the phosphocholine SLBs, it was illustrated that both the chemistry of the lipid headgroups and the packing of lipid acyl chains can substantially affect the particular steps in the interactions between PPN and lipid bilayers. Our findings may help to elucidate the possible mechanisms of PPN interaction with lipid membranes, the toxic behavior and overdosage scenarios of beta-blockers, and provide valuable information for drug development and modification.
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Affiliation(s)
- Ni He
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science Shanghai 201620 China +86-021-67791214
| | - Tao Zhao
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science Shanghai 201620 China +86-021-67791214
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11
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Broad K, Walker SA, Davidovich I, Witwer K, Talmon Y, Wolfram J. Unraveling multilayered extracellular vesicles: Speculation on cause. J Extracell Vesicles 2023; 12:e12309. [PMID: 36732941 PMCID: PMC9895808 DOI: 10.1002/jev2.12309] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 01/17/2023] [Accepted: 01/23/2023] [Indexed: 02/04/2023] Open
Abstract
Extracellular vesicles (EVs) are cell-released, heterogenous nanoparticles that play important roles in (patho)physiological processes through intercellular communication. EVs are often depicted as having a single lipid bilayer, but many studies have demonstrated the existence of multilayered EVs. There has been minimal inquiry into differences between unilamellar and multilamellar EVs in terms of biogenesis mechanisms and functional effects. This commentary speculates on potential causes and roles of multilamellar EVs and serves as a call to action for the research community to unravel the complex layers of EVs.
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Affiliation(s)
- Kelly Broad
- Department of Biochemistry and Molecular BiologyDepartment of Physiology and Biomedical EngineeringDepartment of TransplantationMayo ClinicJacksonvilleFloridaUSA,Skaggs Graduate School of Chemical and Biological SciencesUniversity of Florida Scripps Biomedical ResearchJupiterFloridaUSA
| | - Sierra A. Walker
- Department of Biochemistry and Molecular BiologyDepartment of Physiology and Biomedical EngineeringDepartment of TransplantationMayo ClinicJacksonvilleFloridaUSA
| | - Irina Davidovich
- Department of Chemical Engineering and the Russell Berrie Nanotechnology Institute (RBNI)Technion‐Israel Institute of TechnologyHaifaIsrael
| | - Kenneth Witwer
- Department of Molecular and Comparative PathobiologyThe Johns Hopkins University School of MedicineBaltimoreMarylandUSA,Department of NeurologyThe Johns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Yeshayahu Talmon
- Department of Chemical Engineering and the Russell Berrie Nanotechnology Institute (RBNI)Technion‐Israel Institute of TechnologyHaifaIsrael
| | - Joy Wolfram
- School of Chemical EngineeringThe University of QueenslandBrisbaneQueenslandAustralia,Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandBrisbaneQueenslandAustralia,Department of NanomedicineHouston Methodist Research InstituteHoustonTexasUSA
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12
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Wang Q, Kim H, Halvorsen TM, Chen S, Hayes CS, Buie CR. Leveraging microfluidic dielectrophoresis to distinguish compositional variations of lipopolysaccharide in E. coli. Front Bioeng Biotechnol 2023; 11:991784. [PMID: 36873367 PMCID: PMC9979706 DOI: 10.3389/fbioe.2023.991784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 02/03/2023] [Indexed: 02/18/2023] Open
Abstract
Lipopolysaccharide (LPS) is the unique feature that composes the outer leaflet of the Gram-negative bacterial cell envelope. Variations in LPS structures affect a number of physiological processes, including outer membrane permeability, antimicrobial resistance, recognition by the host immune system, biofilm formation, and interbacterial competition. Rapid characterization of LPS properties is crucial for studying the relationship between these LPS structural changes and bacterial physiology. However, current assessments of LPS structures require LPS extraction and purification followed by cumbersome proteomic analysis. This paper demonstrates one of the first high-throughput and non-invasive strategies to directly distinguish Escherichia coli with different LPS structures. Using a combination of three-dimensional insulator-based dielectrophoresis (3DiDEP) and cell tracking in a linear electrokinetics assay, we elucidate the effect of structural changes in E. coli LPS oligosaccharides on electrokinetic mobility and polarizability. We show that our platform is sufficiently sensitive to detect LPS structural variations at the molecular level. To correlate electrokinetic properties of LPS with the outer membrane permeability, we further examined effects of LPS structural variations on bacterial susceptibility to colistin, an antibiotic known to disrupt the outer membrane by targeting LPS. Our results suggest that microfluidic electrokinetic platforms employing 3DiDEP can be a useful tool for isolating and selecting bacteria based on their LPS glycoforms. Future iterations of these platforms could be leveraged for rapid profiling of pathogens based on their surface LPS structural identity.
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Affiliation(s)
- Qianru Wang
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Hyungseok Kim
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Tiffany M Halvorsen
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Sijie Chen
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Christopher S Hayes
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Cullen R Buie
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
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13
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Tripathi AK, Vishwanatha JK. Role of Anti-Cancer Peptides as Immunomodulatory Agents: Potential and Design Strategy. Pharmaceutics 2022; 14:pharmaceutics14122686. [PMID: 36559179 PMCID: PMC9781574 DOI: 10.3390/pharmaceutics14122686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 11/27/2022] [Accepted: 11/30/2022] [Indexed: 12/05/2022] Open
Abstract
The usage of peptide-based drugs to combat cancer is gaining significance in the pharmaceutical industry. The collateral damage caused to normal cells due to the use of chemotherapy, radiotherapy, etc. has given an impetus to the search for alternative methods of cancer treatment. For a long time, antimicrobial peptides (AMPs) have been shown to display anticancer activity. However, the immunomodulatory activity of anti-cancer peptides has not been researched very extensively. The interconnection of cancer and immune responses is well-known. Hence, a search and design of molecules that can show anti-cancer and immunomodulatory activity can be lead molecules in this field. A large number of anti-cancer peptides show good immunomodulatory activity by inhibiting the pro-inflammatory responses that assist cancer progression. Here, we thoroughly review both the naturally occurring and synthetic anti-cancer peptides that are reported to possess both anti-cancer and immunomodulatory activity. We also assess the structural and biophysical parameters that can be utilized to improve the activity. Both activities are mostly reported by different groups, however, we discuss them together to highlight their interconnection, which can be used in the future to design peptide drugs in the field of cancer therapeutics.
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14
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Benserhir Y, Salaün AC, Geneste F, Oliviero N, Pichon L, Jolivet-Gougeon A. Silicon nanowires-based biosensors for the electrical detection of Escherichia coli. Biosens Bioelectron 2022; 216:114625. [PMID: 35995028 DOI: 10.1016/j.bios.2022.114625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 07/17/2022] [Accepted: 08/03/2022] [Indexed: 11/25/2022]
Abstract
One of the main challenges in terms of public health concerns the prevention of bacterial contamination using rapid, highly sensitive and specific detection techniques. The development of highly sensitive bacterial sensors for Escherichia coli detection based on networks of silicon nanowires has been carried out in this work. The interest of these nano-objects takes advantage in a large contact surface allowing potentially important interactions with bacteria. Their presence induces a change in electrical interaction through the silicon nanowires array and is the basis for the development of silicon nanowires based electrical resistances acting as bacteria sensors. High specificity of these sensors is ensured by chemical functionalization of the nanowires allowing the binding of specific antibodies targeting the lipopolysaccharide (anti-LPS) of E. coli, but not S. aureus. The sensor displays a sensitivity of 83 μA per decade of CFU/mL due to the nanometric dimensions of the nanowires. The electrical measurements ensure the detection of various E. coli concentrations down to 102 CFU/mL. This SiNW biosensor device demonstrated its potential as an alternative tool for real-time bacterial detection as miniaturizable and low-cost integrated electronic sensor compatible with the classical silicon technology.
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Affiliation(s)
- Yousra Benserhir
- Univ Rennes, CNRS, IETR [Institut d'Electronique et des Technologies du numéRique] UMR 6164, F-35000, Rennes, France
| | - Anne-Claire Salaün
- Univ Rennes, CNRS, IETR [Institut d'Electronique et des Technologies du numéRique] UMR 6164, F-35000, Rennes, France.
| | - Florence Geneste
- Univ Rennes, ISCR [Institut des Sciences Chimiques de Rennes] - UMR 6226, F-35000, Rennes, France
| | - Nolwenn Oliviero
- Univ Rennes, INSERM, INRAE, Institut NUMECAN [Nutrition Metabolisms and Cancer], F-35000, Rennes, France
| | - Laurent Pichon
- Univ Rennes, CNRS, IETR [Institut d'Electronique et des Technologies du numéRique] UMR 6164, F-35000, Rennes, France
| | - Anne Jolivet-Gougeon
- Univ Rennes, INSERM, INRAE, Institut NUMECAN [Nutrition Metabolisms and Cancer], F-35000, Rennes, France
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15
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Kum SL, Ho JCS, Parikh AN, Liedberg B. Amphiphilic Membrane Environments Regulate Enzymatic Behaviors of Salmonella Outer Membrane Protease. ACS BIO & MED CHEM AU 2022; 2:73-83. [PMID: 37102179 PMCID: PMC10114716 DOI: 10.1021/acsbiomedchemau.1c00027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
The role of an amphiphilic environment in the functional regulation of integral membrane proteins is well appreciated but how specific amphiphilic surrounding influences the conformational plasticity and function of a protein is less obvious. We focus on the Salmonella phosphoglycerate transport system (pgt)-encoded outer membrane protease E (PgtE), which plays an important role in tissue infiltration and survival of Salmonella enterica. Despite our understanding of its physiological functions, elucidation of its enzymatic behavior in response to the immediate amphiphilic surrounding is lacking. We monitor the proteolytic activity of PgtE reconstituted in Zwittergent 3-12 detergent micelles or a 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) bilayer and examine factors that influence its activity. We find, to our surprise, that PgtE, which is thought to elicit a rapid response toward various substrates, showed hysteretic enzymatic behavior, characterized by a prominent lag phase prior to achieving the exponential steady state in its detergent-stabilized form as well as in the outer membrane embedded native state in live bacteria. The lag phase was abolished under three conditions: preformation of an inactive detergent-stabilized PgtE-substrate complex without lipopolysaccharide (LPS), LPS-bound detergent-stabilized PgtE that had reached steady state velocity, or PgtE reconstituted into a POPC bilayer environment. Interestingly, detergent- and bilayer-stabilized PgtE showed comparable steady-state activity. And strikingly, lipopolysaccharide (LPS) becomes nonessential for the activation of PgtE when the protein is reconstituted in the phospholipid bilayer, contrasting a long-standing notion that LPS is required for proteases belonging to the omptin family to be proteolytically active. These findings suggest intriguing biological nuances for the proteolytic function of PgtE that were not well appreciated previously and offer new perspectives that may generally be applicable for omptins.
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Affiliation(s)
- Siau Ling Kum
- Centre
for Biomimetic Sensor Science, Nanyang Technological
University, 50 Nanyang Drive, 637553 Singapore
- School
of Materials Science and Engineering, Nanyang
Technological University, 50 Nanyang Ave, 639798 Singapore
| | - James C. S. Ho
- Centre
for Biomimetic Sensor Science, Nanyang Technological
University, 50 Nanyang Drive, 637553 Singapore
- School
of Materials Science and Engineering, Nanyang
Technological University, 50 Nanyang Ave, 639798 Singapore
| | - Atul N. Parikh
- Centre
for Biomimetic Sensor Science, Nanyang Technological
University, 50 Nanyang Drive, 637553 Singapore
- School
of Materials Science and Engineering, Nanyang
Technological University, 50 Nanyang Ave, 639798 Singapore
- Department of Chemistry and Department of
Biomedical Engineering, University of California, Davis, California 95616, United States
| | - Bo Liedberg
- Centre
for Biomimetic Sensor Science, Nanyang Technological
University, 50 Nanyang Drive, 637553 Singapore
- School
of Materials Science and Engineering, Nanyang
Technological University, 50 Nanyang Ave, 639798 Singapore
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16
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Meers PR. Membrane Organization Strategies in Vesicular Antibiotic Delivery. J Membr Biol 2022; 255:523-535. [PMID: 35018488 DOI: 10.1007/s00232-021-00210-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 12/06/2021] [Indexed: 01/08/2023]
Abstract
Small molecule antibiotics are often derived from microorganisms that thrive in competitive environments. Their importance as therapeutics for infectious disease in humans has been established over many years. It has now become clear that antibiotic-producing organisms use packaging and delivery in the form of vesicles in many cases. A similar strategy has evolved in recent decades in the pharmaceutical industry for formulation of antibiotic therapies. The top-down approach that has evolved over millions of years in various micro-organisms has generated complex, efficient delivery systems that we are just now beginning to understand. The bottom-up formulation approach involves simple, safe compositions, which are being continually enhanced by trying to add features of which the natural systems inform us. A comparison is made here of these paradigms. Despite the differences, there are a number of common features in the basic physical and biological requirements that must be satisfied. In this review, illustration and comparison of some of these requirements is given, demonstrating the ongoing challenges in this area of research.
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Affiliation(s)
- Paul R Meers
- Department of Plant Biology, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, NJ, USA.
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17
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González-Fernández C, Bringas E, Oostenbrink C, Ortiz I. In silico investigation and surmounting of Lipopolysaccharide barrier in Gram-Negative Bacteria: How far has molecular dynamics Come? Comput Struct Biotechnol J 2022; 20:5886-5901. [PMID: 36382192 PMCID: PMC9636410 DOI: 10.1016/j.csbj.2022.10.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/24/2022] [Accepted: 10/24/2022] [Indexed: 11/29/2022] Open
Abstract
Lipopolysaccharide (LPS), a main component of the outer membrane of Gram-negative bacteria, has crucial implications on both antibiotic resistance and the overstimulation of the host innate immune system. Fighting against these global concerns calls for the molecular understanding of the barrier function and immunostimulatory ability of LPS. Molecular dynamics (MD) simulations have become an invaluable tool for uncovering important findings in LPS research. While the reach of MD simulations for investigating the immunostimulatory ability of LPS has been already outlined, little attention has been paid to the role of MD simulations for exploring its barrier function and synthesis. Herein, we give an overview about the impact of MD simulations on gaining insight into the shield role and synthesis pathway of LPS, which have attracted considerable attention to discover molecules able to surmount antibiotic resistance, either circumventing LPS defenses or disrupting its synthesis. We specifically focus on the enhanced sampling and free energy calculation methods that have been combined with MD simulations to address such research. We also highlight the use of special-purpose MD supercomputers, the importance of appropriate LPS and ions parameterization to obtain reliable results, and the complementary views that MD and wet-lab experiments provide. Thereby, this work, which covers the last five years of research, apart from outlining the phenomena and strategies that are being explored, evidences the valuable insights that are gained by MD, which may be useful to advance antibiotic design, and what the prospects of this in silico method could be in LPS research.
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Affiliation(s)
- Cristina González-Fernández
- Department of Chemical and Biomolecular Engineering, ETSIIT, University of Cantabria, Avda. Los Castros s/n, 39005 Santander, Spain
| | - Eugenio Bringas
- Department of Chemical and Biomolecular Engineering, ETSIIT, University of Cantabria, Avda. Los Castros s/n, 39005 Santander, Spain
| | - Chris Oostenbrink
- Institute for Molecular Modeling and Simulation, BOKU – University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Inmaculada Ortiz
- Department of Chemical and Biomolecular Engineering, ETSIIT, University of Cantabria, Avda. Los Castros s/n, 39005 Santander, Spain
- Corresponding author.
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18
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Abstract
Mg2+ is the most abundant divalent cation in living cells. It is essential for charge neutralization, macromolecule stabilization, and the assembly and activity of ribosomes and as a cofactor for enzymatic reactions. When experiencing low cytoplasmic Mg2+, bacteria adopt two main strategies: They increase the abundance and activity of Mg2+ importers and decrease the abundance of Mg2+-chelating ATP and rRNA. These changes reduce regulated proteolysis by ATP-dependent proteases and protein synthesis in a systemic fashion. In many bacterial species, the transcriptional regulator PhoP controls expression of proteins mediating these changes. The 5' leader region of some mRNAs responds to low cytoplasmic Mg2+ or to disruptions in translation of open reading frames in the leader regions by furthering expression of the associated coding regions, which specify proteins mediating survival when the cytoplasmic Mg2+ concentration is low. Microbial species often utilize similar adaptation strategies to cope with low cytoplasmic Mg2+ despite relying on different genes to do so.
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Affiliation(s)
- Eduardo A Groisman
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut 06536, USA; .,Yale Microbial Sciences Institute, West Haven, Connecticut 06516, USA
| | - Carissa Chan
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut 06536, USA;
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19
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Baxter AM, Jordan LR, Kullappan M, Wittenberg NJ. Tubulation of Supported Lipid Bilayer Membranes Induced by Photosensitized Lipid Oxidation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:5753-5762. [PMID: 33939441 DOI: 10.1021/acs.langmuir.0c03363] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We show that photosensitized phospholipid oxidation, initiated by the lipid-conjugated fluorophore TopFluor-PC, causes defects, namely, membrane tubes and vesicle-like structures, in supported lipid bilayers (SLBs). Lipid oxidation is detrimental to the integrity of the lipid molecules; when oxidized, they undergo a conformational expansion, which causes membrane tubes to protrude from the SLB. Lipid oxidation is verified by FT-IR spectroscopy, and area expansion is observed in Langmuir trough experiments. Upon growing to a critical length, the membrane tubes arising from SLBs rapidly undergo transition to vesicle-like structures. We find a correlation between the maximum tube length and the diameter of the resulting vesicle, suggesting the conservation of the surface area between these features. We use geometric modeling and the measured tube length and vesicle radius to calculate the tube radius; our calculated mean tube diameter of 243 nm is comparable to other groups' experimental findings. In the presence of fluid flow, membrane tubes can be extended to tens to hundreds of microns in length. SLBs composed of saturated lipids resist light-induced tubulation, and the inclusion of the lipophilic antioxidant α-tocopherol attenuates the tubulation process and increases the light intensity threshold for tubulation.
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Affiliation(s)
- Ashley M Baxter
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Luke R Jordan
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Monicka Kullappan
- Department of Chemical & Biomolecular Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Nathan J Wittenberg
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
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20
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Meredith SA, Yoneda T, Hancock AM, Connell SD, Evans SD, Morigaki K, Adams PG. Model Lipid Membranes Assembled from Natural Plant Thylakoids into 2D Microarray Patterns as a Platform to Assess the Organization and Photophysics of Light-Harvesting Proteins. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2006608. [PMID: 33690933 DOI: 10.1002/smll.202006608] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/14/2021] [Indexed: 06/12/2023]
Abstract
Natural photosynthetic "thylakoid" membranes found in green plants contain a large network of light-harvesting (LH) protein complexes. Rearrangement of this photosynthetic machinery, laterally within stacked membranes called "grana", alters protein-protein interactions leading to changes in the energy balance within the system. Preparation of an experimentally accessible model system that allows the detailed investigation of these complex interactions can be achieved by interfacing thylakoid membranes and synthetic lipids into a template comprised of polymerized lipids in a 2D microarray pattern on glass surfaces. This paper uses this system to interrogate the behavior of LH proteins at the micro- and nanoscale and assesses the efficacy of this model. A combination of fluorescence lifetime imaging and atomic force microscopy reveals the differences in photophysical state and lateral organization between native thylakoid and hybrid membranes, the mechanism of LH protein incorporation into the developing hybrid membranes, and the nanoscale structure of the system. The resulting model system within each corral is a high-quality supported lipid bilayer that incorporates laterally mobile LH proteins. Photosynthetic activity is assessed in the hybrid membranes versus proteoliposomes, revealing that commonly used photochemical assays to test the electron transfer activity of photosystem II may actually produce false-positive results.
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Affiliation(s)
- Sophie A Meredith
- School of Physics and Astronomy and The Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Takuro Yoneda
- Graduate School of Agricultural Science and Biosignal Research Center, Kobe University, Rokkodaicho 1-1, Nada, Kobe, 657-8501, Japan
| | - Ashley M Hancock
- School of Physics and Astronomy and The Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Simon D Connell
- School of Physics and Astronomy and The Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Stephen D Evans
- School of Physics and Astronomy and The Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Kenichi Morigaki
- Graduate School of Agricultural Science and Biosignal Research Center, Kobe University, Rokkodaicho 1-1, Nada, Kobe, 657-8501, Japan
| | - Peter G Adams
- School of Physics and Astronomy and The Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
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21
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Arulkumaran N, Lanphere C, Gaupp C, Burns JR, Singer M, Howorka S. DNA Nanodevices with Selective Immune Cell Interaction and Function. ACS NANO 2021; 15:4394-4404. [PMID: 33492943 DOI: 10.1021/acsnano.0c07915] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
DNA nanotechnology produces precision nanostructures of defined chemistry. Expanding their use in biomedicine requires designed biomolecular interaction and function. Of topical interest are DNA nanostructures that function as vaccines with potential advantages over nonstructured nucleic acids in terms of serum stability and selective interaction with human immune cells. Here, we describe how compact DNA nanobarrels bind with a 400-fold selectivity via membrane anchors to white blood immune cells over erythrocytes, without affecting cell viability. The selectivity is based on the preference of the cholesterol lipid anchor for the more fluid immune cell membranes compared to the lower membrane fluidity of erythrocytes. Compacting DNA into the nanostructures gives rise to increased serum stability. The DNA barrels furthermore functionally modulate white blood cells by suppressing the immune response to pro-inflammatory endotoxin lipopolysaccharide. This is likely due to electrostatic or steric blocking of toll-like receptors on white blood cells. Our findings on immune cell-specific DNA nanostructures may be applied for vaccine development, immunomodulatory therapy to suppress septic shock, or the targeting of bioactive substances to immune cells.
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Affiliation(s)
- Nishkantha Arulkumaran
- Division of Medicine, Bloomsbury Institute of Intensive Care Medicine, University College London, London WC1E 6BT, United Kingdom
| | - Conor Lanphere
- Department of Chemistry, Institute of Structural Molecular Biology, University College London, London WC1H 0AJ, United Kingdom
| | - Charlotte Gaupp
- Division of Medicine, Bloomsbury Institute of Intensive Care Medicine, University College London, London WC1E 6BT, United Kingdom
| | - Jonathan R Burns
- Department of Chemistry, Institute of Structural Molecular Biology, University College London, London WC1H 0AJ, United Kingdom
| | - Mervyn Singer
- Division of Medicine, Bloomsbury Institute of Intensive Care Medicine, University College London, London WC1E 6BT, United Kingdom
| | - Stefan Howorka
- Department of Chemistry, Institute of Structural Molecular Biology, University College London, London WC1H 0AJ, United Kingdom
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22
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Kiss B, Bozó T, Mudra D, Tordai H, Herényi L, Kellermayer M. Development, structure and mechanics of a synthetic E. coli outer membrane model. NANOSCALE ADVANCES 2021; 3:755-766. [PMID: 36133844 PMCID: PMC9418885 DOI: 10.1039/d0na00977f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 12/09/2020] [Indexed: 06/16/2023]
Abstract
The outer membrane (OM) of Gram-negative bacteria is a complex asymmetric bilayer containing lipids, lipopolysaccharides (LPS) and proteins. While it is a mechanical and chemical barrier, it is also the primary surface of bacterial recognition processes that involve infection by and of the bacterium. Uncovering the mechanisms of these biological functions has been hampered by the lack of suitable model systems. Here we report the step-by-step assembly of a synthetic OM model from its fundamental components. To enable the efficient formation of a supported lipid bilayer at room temperature, dimyristoyl-phosphocholine (DMPC) was used as the lipid component to which we progressively added LPS and OM proteins. The assembled system enabled us to explore the contribution of the molecular components to the topographical structure and stability of the OM. We found that LPS prefers solid-state membrane regions and forms stable vesicles in the presence of divalent cations. LPS can gradually separate from DMPC membranes to form independent vesicles, pointing at the dynamic nature of the lipid-LPS system. The addition of OM proteins from E. coli and saturating levels of LPS to DMPC liposomes resulted in a thicker and more stable bilayer the surface of which displayed a nanoscale texture formed of parallel, curved, long (>500 nm) stripes spaced apart with a 15 nm periodicity. The synthetic membrane may facilitate the investigation of binding and recognition processes on the surface of Gram-negative bacteria.
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Affiliation(s)
- Bálint Kiss
- Department of Biophysics and Radiation Biology, Semmelweis University Budapest Hungary
| | - Tamás Bozó
- Department of Biophysics and Radiation Biology, Semmelweis University Budapest Hungary
| | - Dorottya Mudra
- Department of Biophysics and Radiation Biology, Semmelweis University Budapest Hungary
| | - Hedvig Tordai
- Department of Biophysics and Radiation Biology, Semmelweis University Budapest Hungary
| | - Levente Herényi
- Department of Biophysics and Radiation Biology, Semmelweis University Budapest Hungary
| | - Miklós Kellermayer
- Department of Biophysics and Radiation Biology, Semmelweis University Budapest Hungary
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23
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Wojciechowska M, Miszkiewicz J, Trylska J. Conformational Changes of Anoplin, W-MreB 1-9, and (KFF) 3K Peptides near the Membranes. Int J Mol Sci 2020; 21:ijms21249672. [PMID: 33352981 PMCID: PMC7766051 DOI: 10.3390/ijms21249672] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 12/07/2020] [Accepted: 12/14/2020] [Indexed: 12/12/2022] Open
Abstract
Many peptides interact with biological membranes, but elucidating these interactions is challenging because cellular membranes are complex and peptides are structurally flexible. To contribute to understanding how the membrane-active peptides behave near the membranes, we investigated peptide structural changes in different lipid surroundings. We focused on two antimicrobial peptides, anoplin and W-MreB1–9, and one cell-penetrating peptide, (KFF)3K. Firstly, by using circular dichroism spectroscopy, we determined the secondary structures of these peptides when interacting with micelles, liposomes, E. coli lipopolysaccharides, and live E. coli bacteria. The peptides were disordered in the buffer, but anoplin and W-MreB1–9 displayed lipid-induced helicity. Yet, structural changes of the peptide depended on the composition and concentration of the membranes. Secondly, we quantified the destructive activity of peptides against liposomes by monitoring the release of a fluorescent dye (calcein) from the liposomes treated with peptides. We observed that only for anoplin and W-MreB1–9 calcein leakage from liposomes depended on the peptide concentration. Thirdly, bacterial growth inhibition assays showed that peptide conformational changes, evoked by the lipid environments, do not directly correlate with the antimicrobial activity of the peptides. However, understanding the relation between peptide structural properties, mechanisms of membrane disruption, and their biological activities can guide the design of membrane-active peptides.
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Affiliation(s)
- Monika Wojciechowska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland;
- Correspondence: (M.W.); (J.T.)
| | - Joanna Miszkiewicz
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland;
- College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
| | - Joanna Trylska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland;
- Correspondence: (M.W.); (J.T.)
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24
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Bhattacharyya D, Bhunia A. Gut-Brain axis in Parkinson's disease etiology: The role of lipopolysaccharide. Chem Phys Lipids 2020; 235:105029. [PMID: 33338469 DOI: 10.1016/j.chemphyslip.2020.105029] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 12/05/2020] [Accepted: 12/10/2020] [Indexed: 12/26/2022]
Abstract
Recent studies highlight the initiation of Parkinson's disease (PD) in the gastrointestinal tract, decades before the manifestations in the central nervous system (CNS). This gut-brain axis of neurodegenerative diseases defines the critical role played by the unique microbial composition of the "second brain" formed by the enteric nervous system (ENS). Compromise in the enteric wall can result in the translocation of gut-microbiota along with their metabolites into the system that can affect the homeostatic machinery. The released metabolites can associate with protein substrates affecting several biological pathways. Among these, the bacterial endotoxin from Gram-negative bacteria, i.e., Lipopolysaccharide (LPS), has been implicated to play a definite role in progressive neurodegeneration. The molecular interaction of the lipid metabolites can have a direct neuro-modulatory effect on homeostatic protein components that can be transported to the CNS via the vagus nerve. α-synuclein (α-syn) is one such partner protein, the molecular interactions with which modulate its overall fibrillation propensity in the system. LPS interaction has been shown to affect the protein's aggregation kinetics in an alternative inflammatory pathway of PD pathogenesis. Several other lipid contents from the bacterial membranes could also be responsible for the initiation of α-syn amyloidogenesis. The present review will focus on the intermolecular interactions of α-syn with bacterial lipid components, particularly LPS, with a definite clinical manifestation in PD pathogenesis. However, deconvolution of the sequence of interaction events from the ENS to its propagation in the CNS is not easy or obvious. Nevertheless, the characterization of these lipid-mediated structures is a step towards realizing the novel targets in the pre-emptive diagnoses of PD. This comprehensive description should prompt the correlation of potential risk of amyloidogenesis upon detection of specific paradigm shifts in the microbial composition of the gut.
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Affiliation(s)
- Dipita Bhattacharyya
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata, 700054, India
| | - Anirban Bhunia
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata, 700054, India.
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25
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Hu S, Zhao T, Li H, Cheng D, Sun Z. Effect of tetracaine on dynamic reorganization of lipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183351. [PMID: 32416192 DOI: 10.1016/j.bbamem.2020.183351] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 04/18/2020] [Accepted: 05/07/2020] [Indexed: 12/16/2022]
Abstract
To understand the intrinsic influence of a drug on lipid membranes is of critical importance in pharmacological science. Herein, we report fluorescence microscopy analysis of the interaction between the local anesthetic tetracaine (TTC) and planar supported lipid bilayers (SLBs), as model membranes. Our results show that TTC increases lipid chain mobility, destabilizes the SLBs and remarkably induces membrane disruption and solubilization. Upon TTC binding, a local curvature change in the bilayer was observed, which led to the subsequent formation of up to 20-μm-long flexible lipid tubules as well as the formation of micron-size holes. Quantitative analysis revealed that membrane solubilization process can be divided into two distinct different stages as a function of TTC concentration. In the first stage (<800 μM), the bilayer disruption profiles fit well to a Langmuir isotherm, while in the second stage (800 μM-25 mM), TTC solubilizes the membrane in a detergent-like manner. Notably, the onset of membrane solubilization occurred below the critical micelle concentration (cmc) of TTC, indicating a local accumulation of the drug in the membrane. Additionally, cholesterol increases the insertion of TTC into the membrane and thus promotes the solubilization effect of TTC on lipid bilayers. These findings may help to elucidate the possible mechanisms of TTC interaction with lipid membranes, the dose dependent toxicity attributed to local anesthetics, as well as provide valuable information for drug development and modification.
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Affiliation(s)
- Shipeng Hu
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China
| | - Tao Zhao
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China.
| | - Hewen Li
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China
| | - Danling Cheng
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China
| | - Zhihua Sun
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China
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26
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Sharma P, Parthasarathi S, Patil N, Waskar M, Raut JS, Puranik M, Ayappa KG, Basu JK. Assessing Barriers for Antimicrobial Penetration in Complex Asymmetric Bacterial Membranes: A Case Study with Thymol. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:8800-8814. [PMID: 32609530 DOI: 10.1021/acs.langmuir.0c01124] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The bacterial cell envelope is a complex multilayered structure evolved to protect bacteria in hostile environments. An understanding of the molecular basis for the interaction and transport of antibacterial therapeutics with the bacterial cell envelope will enable the development of drug molecules to combat bacterial infections and suppress the emergence of drug-resistant strains. Here we report the successful creation of an in vitro supported lipid bilayer (SLB) platform of the outer membrane (OM) of E. coli, an archetypical Gram-negative bacterium, containing the full smooth lipopolysaccharide (S-LPS) architecture of the membrane. Using this platform, we performed fluorescence correlation spectroscopy (FCS) in combination with molecular dynamics (MD) simulations to measure lipid diffusivities and provide molecular insights into the transport of natural antimicrobial agent thymol. Lipid diffusivities measured on symmetric supported lipid bilayers made up of inner membrane lipids show a distinct increase in the presence of thymol as also corroborated by MD simulations. However, lipid diffusivities in the asymmetric OM consisting of only S-LPS are invariant upon exposure to thymol. Increasing the phospholipid content in the LPS-containing outer leaflet improved the penetration toward thymol as reflected in slightly higher relative diffusivity changes in the inner leaflet when compared with the outer leaflet. Free-energy computations reveal the presence of a barrier (∼6 kT) only in the core-saccharide region of the OM for the translocation of thymol while the external O-antigen part is easily traversed. In contrast, thymol spontaneously inserts into the inner membrane. In addition to providing leaflet-resolved penetration barriers in bacterial membranes, we also assess the ability of small molecules to penetrate various membrane components. With rising bacterial resistance, our study opens up the possibility of screening potential antimicrobial drug candidates using these realistic model platforms for Gram-negative bacteria.
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Affiliation(s)
| | | | - Nivedita Patil
- Unilever RD Bangalore, 64 Main Road, Whitefield, Bangalore 560066, India
| | - Morris Waskar
- Unilever RD Bangalore, 64 Main Road, Whitefield, Bangalore 560066, India
| | - Janhavi S Raut
- Unilever RD Bangalore, 64 Main Road, Whitefield, Bangalore 560066, India
| | - Mrinalini Puranik
- Unilever RD Bangalore, 64 Main Road, Whitefield, Bangalore 560066, India
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27
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Santos JC, Boucher D, Schneider LK, Demarco B, Dilucca M, Shkarina K, Heilig R, Chen KW, Lim RYH, Broz P. Human GBP1 binds LPS to initiate assembly of a caspase-4 activating platform on cytosolic bacteria. Nat Commun 2020; 11:3276. [PMID: 32581219 PMCID: PMC7314798 DOI: 10.1038/s41467-020-16889-z] [Citation(s) in RCA: 152] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/01/2020] [Indexed: 01/16/2023] Open
Abstract
The human non-canonical inflammasome controls caspase-4 activation and gasdermin-D-dependent pyroptosis in response to cytosolic bacterial lipopolysaccharide (LPS). Since LPS binds and oligomerizes caspase-4, the pathway is thought to proceed without dedicated LPS sensors or an activation platform. Here we report that interferon-induced guanylate-binding proteins (GBPs) are required for non-canonical inflammasome activation by cytosolic Salmonella or upon cytosolic delivery of LPS. GBP1 associates with the surface of cytosolic Salmonella seconds after bacterial escape from their vacuole, initiating the recruitment of GBP2-4 to assemble a GBP coat. The GBP coat then promotes the recruitment of caspase-4 to the bacterial surface and caspase activation, in absence of bacteriolysis. Mechanistically, GBP1 binds LPS with high affinity through electrostatic interactions. Our findings indicate that in human epithelial cells GBP1 acts as a cytosolic LPS sensor and assembles a platform for caspase-4 recruitment and activation at LPS-containing membranes as the first step of non-canonical inflammasome signaling. Detection of LPS derived from Gram-negative bacteria by innate immune receptors is a critical step in the host response. Here Santos and colleagues show human GBP1 binds to LPS resulting in non-canonical inflammasome activation.
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Affiliation(s)
- José Carlos Santos
- Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland
| | - Dave Boucher
- Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland
| | | | - Benjamin Demarco
- Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland
| | - Marisa Dilucca
- Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland
| | - Kateryna Shkarina
- Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland
| | - Rosalie Heilig
- Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland
| | - Kaiwen W Chen
- Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland
| | - Roderick Y H Lim
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056, Basel, Switzerland
| | - Petr Broz
- Department of Biochemistry, University of Lausanne, Chemin des Boveresses 155, 1066, Epalinges, Switzerland.
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28
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Antibody Binding to the O-Specific Antigen of Pseudomonas aeruginosa O6 Inhibits Cell Growth. Antimicrob Agents Chemother 2020; 64:AAC.02168-19. [PMID: 32015038 DOI: 10.1128/aac.02168-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 01/24/2020] [Indexed: 01/24/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that is inherently resistant to many antibiotics and represents an increasing threat due to the emergence of drug-resistant strains. There is a pressing need to develop innovative antimicrobials against this pathogen. In this study, we identified the O-specific antigen (OSA) of P. aeruginosa serotype O6 as a novel target for therapeutic intervention. Binding of monoclonal antibodies and antigen-binding fragments therefrom to O6 OSA leads to rapid outer membrane destabilization and inhibition of cell growth. The antimicrobial effect correlated directly with antibody affinity. Antibody binding to the O antigen of a second lipopolysaccharide (LPS) type present in P. aeruginosa or to the LPS core did not affect cell viability. Atomic force microscopy showed that antibody binding to OSA resulted in early flagellum loss, formation of membrane blebs, and eventually complete outer membrane loss. We hypothesize that antibody binding to OSA disrupts a key interaction in the P. aeruginosa outer membrane.
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29
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Kukreti H, Li FC, Singh K, Sodhi R, Kishen A. Efficacy of bioactive nanoparticles on tissue-endotoxin induced suppression of stem cell viability, migration and differentiation. Int Endod J 2020; 53:859-870. [PMID: 32068891 DOI: 10.1111/iej.13283] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 02/15/2020] [Accepted: 02/17/2020] [Indexed: 12/22/2022]
Abstract
AIM To characterize a lipopolysaccharide (LPS)-treated dentine tissue model (LPS dentine) to analyse the efficacy of polycationic chitosan nanoparticles (CSnp) and/or dexamethasone conjugate chitosan nanoparticles (Dex-CSnp) on the viability/differentiation potential of stem cells from apical papilla (SCAP) when exposed to LPS dentine. A further aim was to understand the effect of macrophage-dependent inflammation on SCAP migration in the presence of LPS dentine. METHODOLOGY A total of 88 dentine slabs were used. TOF-SIMS analysis was performed amongst the LPS-treated and untreated dentine groups (n = 2/group). The study was conducted using four dentine groups: no treatment (control); LPS treatment only; LPS treatment followed by CSnp conditioning; and LPS treatment followed by Dex-CSnp conditioning groups. SCAP adherence, viability, differentiation and biomineralization potential on dentine from different groups were studied using fluorescent and scanning electron microscopy. Inflammation by macrophages in response to LPS dentine was quantified, and effect on SCAP migration was analysed. Statistical analysis was performed using Student's t-test with a significance level of P < 0.05. RESULT TOF-SIMS analysis confirmed LPS contamination. LPS dentine affected SCAP viability but not adherence to dentine (P < 0.001). Conditioning of LPS dentine with either nanoparticles improved SCAP viability (P < 0.01) and rescued other LPS related adverse effects on SCAPs, such as F-actin disruption, decrease in differentiation/biomineralization potential. IL-6 produced by macrophages in response to LPS-treated dentine impeded SCAP migration (P < 0.001), diminished on CSnp and Dex-CSnp conditioning groups (P < 0.01). CONCLUSION This study developed an LPS-dentine model and highlighted the ability of CSnp and Dex-CSnp to promote stem cell viability, migration, differentiation potential and reduce inflammation, providing an environment conducive for tissue regeneration/repair.
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Affiliation(s)
- H Kukreti
- Faculty of Dentistry, Dental Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - F-C Li
- Faculty of Dentistry, Dental Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - K Singh
- Faculty of Dentistry, Dental Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - R Sodhi
- Ontario Centre for the Characterization of Advanced Materials (OCCAM), Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - A Kishen
- Faculty of Dentistry, Dental Research Institute, University of Toronto, Toronto, Ontario, Canada
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30
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Gan BH, Siriwardena TN, Javor S, Darbre T, Reymond JL. Fluorescence Imaging of Bacterial Killing by Antimicrobial Peptide Dendrimer G3KL. ACS Infect Dis 2019; 5:2164-2173. [PMID: 31618574 DOI: 10.1021/acsinfecdis.9b00299] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We recently discovered that peptide dendrimers such as G3KL ((KL)8(KKL)4(KKL)2KKL, K = branching l-lysine) exert strong activity against Gram-negative bacteria including Pseudomonas aeruginosa, Acinetobacter baumannii, and Escherichia coli. Herein, we report a detailed mechanistic study using fluorescence labeled analogs bearing fluorescein (G3KL-Fluo) or dansyl (G3KL-Dansyl), which show a similar bioactivity profile as G3KL. Imaging bacterial killing by super-resolution stimulated emission depletion (STED) microscopy, time-lapse imaging, and transmission electron microscopy (TEM) reveals that the dendrimer localizes at the bacterial membrane, induces membrane depolarization and permeabilization, and destroys the outer leaflet and the inner membrane. G3KL accumulates in bacteria against which it is active; however, it only weakly penetrates into eukaryotic cells without inducing significant toxicity. G3KL furthermore binds to lipopolysaccharide (LPS) and inhibits the LPS induced release of TNF-α by macrophages, similarly to polymyxin B. Taken together, these experiments show that G3KL behaves as a potent membrane disruptive antimicrobial peptide.
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Affiliation(s)
- Bee-Ha Gan
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Thissa N. Siriwardena
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Sacha Javor
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Tamis Darbre
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Jean-Louis Reymond
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
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31
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Galván Márquez IJ, McKay B, Wong A, Cheetham JJ, Bean C, Golshani A, Smith ML. Mode of action of nisin on Escherichia coli. Can J Microbiol 2019; 66:161-168. [PMID: 31743042 DOI: 10.1139/cjm-2019-0315] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nisin is a class I polycyclic bacteriocin produced by the bacterium Lactococcus lactis, which is used extensively as a food additive to inhibit the growth of foodborne Gram-positive bacteria. Nisin also inhibits growth of Gram-negative bacteria when combined with membrane-disrupting chelators such as citric acid. To gain insight into nisin's mode of action, we analyzed chemical-genetic interactions and identified nisin-sensitive Escherichia coli strains in the Keio library of knockout mutants. The most sensitive mutants fell into two main groups. The first group accords with the previously proposed mode of action based on studies with Gram-positive bacteria, whereby nisin interacts with factors involved in cell wall, membrane, envelope biogenesis. We identified an additional, novel mode of action for nisin based on the second group of sensitive mutants that involves cell cycle and DNA replication, recombination, and repair. Further analyses supported these two distinct modes of action.
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Affiliation(s)
- Imelda J Galván Márquez
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.,Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada
| | - Bruce McKay
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.,Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada
| | - Alex Wong
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.,Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada
| | - James J Cheetham
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.,Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada
| | - Cody Bean
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.,Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada
| | - Ashkan Golshani
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.,Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada
| | - Myron L Smith
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.,Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada
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32
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Adekoya I, Obadina A, Olorunfemi M, Akande O, Landschoot S, De Saeger S, Njobeh P. Occurrence of bacteria and endotoxins in fermented foods and beverages from Nigeria and South Africa. Int J Food Microbiol 2019; 305:108251. [PMID: 31229696 DOI: 10.1016/j.ijfoodmicro.2019.108251] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 06/10/2019] [Accepted: 06/11/2019] [Indexed: 02/01/2023]
Abstract
In Africa, fermented foods and beverages play significant roles in contributing to food security. Endotoxins are ubiquitous heat stable lipopolysaccharide (LPS) complexes situated in the outer cell membranes of Gram-negative bacteria. This study evaluated the microbiological quality of fermented foods (ogiri, ugba, iru, ogi and ogi baba) and beverages (mahewu and umqombothi) from selected Nigerian and South African markets. The bacterial diversity of the fermented foods was also investigated and the identity of the isolates confirmed by biochemical and molecular methods. Isolate grouping was established through hierarchal clustering and the samples were further investigated for endotoxin production with the chromogenic Limulus Amoebocyte Lysate assay. The total aerobic count of the samples ranged from 5.7 to 10.8 Log CFU/g. Fourteen bacteria genera were detected with most of the isolates being members of the Enterobacteriaceae family. Sphingomonas paucimobilis and Escherichia coli were the dominant Gram-negative bacterial species detected. There were considerable variations in the concentrations of endotoxins produced and the lowest endotoxin concentration was found in ogi (4.3 × 10 EU/g) and the highest in iru (5.5 × 104 EU/g) while, 44% of umqombothi samples had endotoxins. Ogi baba samples had better microbial quality than other samples due to its reduced bacterial load and endotoxin levels. There was a strong positive (r = 0.714, r = 0.996) and significant (p < 0.01) correlation between the endotoxin levels and bacterial loads of the samples. Some previously unreported species of bacteria found in the fermented foods included Aeromonas haemolyticus and Rhizobium radiobacter. This is the first comprehensive report on endotoxins in fermented foods and beverages in Africa. Furthermore, the occurrence of pathogenic bacteria and toxins in the foods and beverages is of serious concern that calls for immediate action.
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Affiliation(s)
- Ifeoluwa Adekoya
- Department of Biotechnology and Food Technology, University of Johannesburg, Johannesburg, South Africa.
| | - Adewale Obadina
- Department of Food Science and Technology, Federal University of Agriculture, Abeokuta, Nigeria
| | | | - Olamide Akande
- Department of Food Science and Technology, Federal University of Technology, Akure, Nigeria
| | - Sofie Landschoot
- Department of Applied Bioscience Engineering, Ghent University, B-9000, Belgium
| | - Sarah De Saeger
- Centre of Excellence in Mycotoxicology and Public Health, Ghent University, B-9000, Belgium
| | - Patrick Njobeh
- Department of Biotechnology and Food Technology, University of Johannesburg, Johannesburg, South Africa
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Maktabi S, Schertzer JW, Chiarot PR. Dewetting-induced formation and mechanical properties of synthetic bacterial outer membrane models (GUVs) with controlled inner-leaflet lipid composition. SOFT MATTER 2019; 15:3938-3948. [PMID: 31011738 PMCID: PMC6647036 DOI: 10.1039/c9sm00223e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The double-membrane cellular envelope of Gram-negative bacteria enables them to endure harsh environments and represents a barrier to many clinically available antibiotics. The outer membrane (OM) is exposed to the environment and is the first point of contact involved in bacterial processes such as signaling, pathogenesis, and motility. As in the cytoplasmic membrane, the OM in Gram-negative bacteria has a phospholipid-rich inner leaflet and an outer leaflet that is predominantly composed of lipopolysaccharide (LPS). We report on a microfluidic technique for fabricating monodisperse asymmetric giant unilamellar vesicles (GUVs) possessing the Gram-negative bacterial OM lipid composition. Our continuous microfluidic fabrication technique generates 50-150 μm diameter water-in-oil-in-water double emulsions at high-throughput. The water-oil and oil-water interfaces facilitate the self-assembly of phospholipid and LPS molecules to create the inner and outer leaflets of the lipid bilayer, respectively. The double emulsions have ultrathin oil shells, which minimizes the amount of residual organic solvent that remains trapped between the leaflets of the GUV membrane. An extraction process by ethanol and micropipette aspiration of the ultrathin oil shells triggers an adhesive interaction between the two lipid monolayers assembled on the water-oil and oil-water interfaces (i.e., dewetting transition), forcing them to contact and form a lipid bilayer membrane. The effect of different inner-leaflet lipid compositions on the emulsion/vesicle stability and the dewetting transition is investigated. We also report on the values for bending and area expansion moduli of synthetic asymmetric model membranes with lipid composition/architecture that is physiologically relevant to the OM in Pseudomonas aeruginosa bacteria.
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Affiliation(s)
- Sepehr Maktabi
- Department of Mechanical Engineering, State University of New York at Binghamton, Binghamton, NY, USA.
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Kubicek-Sutherland JZ, Vu DM, Noormohamed A, Mendez HM, Stromberg LR, Pedersen CA, Hengartner AC, Klosterman KE, Bridgewater HA, Otieno V, Cheng Q, Anyona SB, Ouma C, Raballah E, Perkins DJ, McMahon BH, Mukundan H. Direct detection of bacteremia by exploiting host-pathogen interactions of lipoteichoic acid and lipopolysaccharide. Sci Rep 2019; 9:6203. [PMID: 30996333 PMCID: PMC6470174 DOI: 10.1038/s41598-019-42502-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 03/28/2019] [Indexed: 12/16/2022] Open
Abstract
Bacteremia is a leading cause of death in sub-Saharan Africa where childhood mortality rates are the highest in the world. The early diagnosis of bacteremia and initiation of treatment saves lives, especially in high-disease burden areas. However, diagnosing bacteremia is challenging for clinicians, especially in children presenting with co-infections such as malaria and HIV. There is an urgent need for a rapid method for detecting bacteremia in pediatric patients with co-morbidities to inform treatment. In this manuscript, we have developed and clinically validated a novel method for the direct detection of amphiphilic pathogen biomarkers indicative of bacteremia, directly in aqueous blood, by mimicking innate immune recognition. Specifically, we have exploited the interaction of amphiphilic pathogen biomarkers such as lipopolysaccharides (LPS) from Gram-negative bacteria and lipoteichoic acids (LTA) from Gram-positive bacteria with host lipoprotein carriers in blood, in order to develop two tailored assays – lipoprotein capture and membrane insertion – for their direct detection. Our assays demonstrate a sensitivity of detection of 4 ng/mL for LPS and 2 ng/mL for LTA using a waveguide-based optical biosensor platform that was developed at LANL. In this manuscript, we also demonstrate the application of these methods for the detection of LPS in serum from pediatric patients with invasive Salmonella Typhimurium bacteremia (n = 7) and those with Staphylococcal bacteremia (n = 7) with 100% correlation with confirmatory culture. Taken together, these results demonstrate the significance of biochemistry in both our understanding of host-pathogen biology, and development of assay methodology, as well as demonstrate a potential new approach for the rapid, sensitive and accurate diagnosis of bacteremia at the point of need.
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Affiliation(s)
- Jessica Z Kubicek-Sutherland
- Physical Chemistry and Applied Spectroscopy, Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States
| | - Dung M Vu
- Physical Chemistry and Applied Spectroscopy, Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States
| | - Aneesa Noormohamed
- Physical Chemistry and Applied Spectroscopy, Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States
| | - Heather M Mendez
- Department of Biomedical Engineering, University of New Mexico, Albuquerque, New Mexico, United States
| | - Loreen R Stromberg
- Physical Chemistry and Applied Spectroscopy, Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States.,Department of Biomedical Engineering, University of New Mexico, Albuquerque, New Mexico, United States
| | - Christine A Pedersen
- Physical Chemistry and Applied Spectroscopy, Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States
| | - Astrid C Hengartner
- Physical Chemistry and Applied Spectroscopy, Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States
| | - Katja E Klosterman
- Physical Chemistry and Applied Spectroscopy, Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States
| | - Haley A Bridgewater
- Physical Chemistry and Applied Spectroscopy, Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States
| | - Vincent Otieno
- University of New Mexico/KEMRI Laboratories of Parasitic and Viral Diseases, Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Qiuying Cheng
- Center for Global Health, Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, United States
| | - Samuel B Anyona
- Department of Medical Biochemistry, School of Medicine, Maseno University, Maseno, Kenya and University of New Mexico/KEMRI Laboratories of Parasitic and Viral Diseases, Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Collins Ouma
- Department of Biomedical Sciences and Technology, School of Public Health and Community Development, Maseno University, Maseno, Kenya and University of New Mexico/KEMRI Laboratories of Parasitic and Viral Diseases, Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Evans Raballah
- Department of Medical Laboratory Science, School of Public Health, Biomedical Sciences and Technology, Masinde Muliro University of Science and Technology, Kakamega, Kenya and University of New Mexico/KEMRI Laboratories of Parasitic and Viral Diseases, Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Douglas J Perkins
- University of New Mexico/KEMRI Laboratories of Parasitic and Viral Diseases, Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya.,Center for Global Health, Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, United States
| | - Benjamin H McMahon
- Theoretical Biology and Biophysics, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States
| | - Harshini Mukundan
- Physical Chemistry and Applied Spectroscopy, Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States.
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Uzoechi SC, Abu-Lail NI. Changes in Cellular Elasticities and Conformational Properties of Bacterial Surface Biopolymers of Multidrug-Resistant Escherichia coli (MDR- E. coli) Strains in Response to Ampicillin. ACTA ACUST UNITED AC 2019; 5. [PMID: 31179402 PMCID: PMC6550352 DOI: 10.1016/j.tcsw.2019.100019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The roles of the thicknesses and grafting densities of the surface biopolymers of four multi-drug resistant (MDR) Escherichia coli bacterial strains that varied in their biofilm formation in controlling cellular elasticities after exposure to ampicillin were investigated using atomic force microscopy. Exposure to ampicillin was carried out at minimum inhibitory concentrations for different duration times. Our results indicated that the four strains resisted ampicillin through variable mechanisms. Strain A5 did not change its cellular properties upon exposure to ampicillin and as such resisted ampicillin through dormancy. Strain H5 increased its biopolymer brush thickness, adhesion and biofilm formation and kept its roughness, surface area and cell elasticity unchanged upon exposure to ampicillin. As such, this strain likely limits the diffusion of ampicillin by forming strong biofilms. At three hours’ exposure to ampicillin, strains D4 and A9 increased their roughness, surface areas, biofilm formation, and brush thicknesses and decreased their elasticities. Therefore, at short exposure times to ampicillin, these strains resisted ampicillin through forming strong biofilms that impede ampicillin diffusion. At eight hours’ exposure to ampicillin, strains D4 and A9 collapsed their biopolymers, increased their apparent grafting densities and increased their cellular elasticities. Therefore, at long exposure times to ampicillin, cells utilized their higher rigidity to reduce the diffusion of ampicillin into the cells. The findings of this study clearly point to the potential of using the nanoscale characterization of MDR bacterial properties as a means to monitor cell modifications that enhance “phenotypic antibiotic resistance”.
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Affiliation(s)
- Samuel C Uzoechi
- Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164.,Department of Biomedical Technology, Federal University of Technology, Owerri, PMB 1526, Owerri, Nigeria
| | - Nehal I Abu-Lail
- Department of Biomedical Engineering, The University of Texas at San Antonio, San Antonio, TX, 78249
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36
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Traini G, Ruiz-de-Angulo A, Blanco-Canosa JB, Zamacola Bascarán K, Molinaro A, Silipo A, Escors D, Mareque-Rivas JC. Cancer Immunotherapy of TLR4 Agonist-Antigen Constructs Enhanced with Pathogen-Mimicking Magnetite Nanoparticles and Checkpoint Blockade of PD-L1. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1803993. [PMID: 30569516 DOI: 10.1002/smll.201803993] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 11/07/2018] [Indexed: 05/10/2023]
Abstract
Despite the tremendous potential of Toll-like receptor 4 (TLR4) agonists in vaccines, their efficacy as monotherapy to treat cancer has been limited. Only some lipopolysaccharides (LPS) isolated from particular bacterial strains or structures like monophosphoryl lipid A (MPLA) derived from lipooligosaccharide (LOS), avoid toxic overactivation of innate immune responses while retaining adequate immunogenicity to act as adjuvants. Here, different LOS structures are incorporated into nanoparticle-filled phospholipid micelles for efficient vaccine delivery and more potent cancer immunotherapy. The structurally unique LOS of the plant pathogen Xcc is incorporated into phospholipid micelles encapsulating iron oxide nanoparticles, producing stable pathogen-mimicking nanostructures suitable for targeting antigen presenting cells in the lymph nodes. The antigen is conjugated via a hydrazone bond, enabling rapid, easy-to-monitor and high-yield antigen ligation at low concentrations. The protective effect of these constructs is investigated against a highly aggressive model for tumor immunotherapy. The results show that the nanovaccines lead to a higher-level antigen-specific cytotoxic T lymphocyte (CTL) effector and memory responses, which when combined with abrogation of the immunosuppressive programmed death-ligand 1 (PD-L1), provide 100% long-term protection against repeated tumor challenge. This nanovaccine platform in combination with checkpoint inhibition of PD-L1 represents a promising approach to improve the cancer immunotherapy of TLR4 agonists.
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Affiliation(s)
- Giordano Traini
- CIC biomaGUNE, Paseo Miramón 182, 20014, San Sebastián, Spain
| | | | | | | | - Antonio Molinaro
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte Sant' Angelo, Via Cintia 4, 80126, Napoli, Italy
| | - Alba Silipo
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte Sant' Angelo, Via Cintia 4, 80126, Napoli, Italy
| | - David Escors
- Navarrabiomed-Biomedical Research Centre, Fundación Miguel Servet-IdISNA, Complejo Hospitalario de Navarra, 31008, Pamplona, Spain
| | - Juan C Mareque-Rivas
- Department of Chemistry and Centre for NanoHealth, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
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37
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Zhong Y, Wang G. Three-Dimensional Heterogeneous Structure Formation on a Supported Lipid Bilayer Disclosed by Single-Particle Tracking. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:11857-11865. [PMID: 30170491 DOI: 10.1021/acs.langmuir.8b01690] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Three-dimensional (3D) single-particle tracking was employed to study the lipid membrane morphology change at different pHs on glass supported lipid bilayers (SLBs) [1,2-dioleoyl- sn-glycero-3-phosphoethanolamine/1,2-dioleoyl- sn-glycero-3-phospho-l-serine (sodium salt)/1,2-dioleoyl- sn-glycero-3-phosphocholine = 5:3:2]. Fluorescently tagged, carboxylated polystyrene nanoparticles (of 100 nm) were used as the probes. At neutral pHs, the particles' diffusion was close to two-dimensional Brownian motion, indicating a mainly planar structure of the SLBs. When the environmental pH was tuned to be basic at 10.0, transiently confined diffusions within small areas were frequently observed. These confinements had a lateral dimension of 100-200 nm. Most interestingly, they showed 3D bulged structures protruding from the planar lipid bilayer. The particles were trapped by these 3D structures for a short period of time (∼0.75 s), with an estimated escape activation energy of ∼4.2 kB T. Nonuniform distribution of pH-sensitive lipids in the membrane was proposed to explain the formation of these 3D heterogeneous structures. This work suggests that the geometry of the 3D lipid structures can play a role in tuning the particle-lipid surface interactions. It sheds new light on the origin of lateral heterogeneity on the lipid membrane.
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Affiliation(s)
- Yaning Zhong
- Department of Chemistry , North Carolina State University , Raleigh , North Carolina 27695-8204 , United States
| | - Gufeng Wang
- Department of Chemistry , North Carolina State University , Raleigh , North Carolina 27695-8204 , United States
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38
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Adams PG, Vasilev C, Hunter CN, Johnson MP. Correlated fluorescence quenching and topographic mapping of Light-Harvesting Complex II within surface-assembled aggregates and lipid bilayers. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2018; 1859:1075-1085. [PMID: 29928860 PMCID: PMC6135645 DOI: 10.1016/j.bbabio.2018.06.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 06/11/2018] [Accepted: 06/15/2018] [Indexed: 01/30/2023]
Abstract
Light-Harvesting Complex II (LHCII) is a chlorophyll-protein antenna complex that efficiently absorbs solar energy and transfers electronic excited states to photosystems I and II. Under excess light intensity LHCII can adopt a photoprotective state in which excitation energy is safely dissipated as heat, a process known as Non-Photochemical Quenching (NPQ). In vivo NPQ is triggered by combinatorial factors including transmembrane ΔpH, PsbS protein and LHCII-bound zeaxanthin, leading to dramatically shortened LHCII fluorescence lifetimes. In vitro, LHCII in detergent solution or in proteoliposomes can reversibly adopt an NPQ-like state, via manipulation of detergent/protein ratio, lipid/protein ratio, pH or pressure. Previous spectroscopic investigations revealed changes in exciton dynamics and protein conformation that accompany quenching, however, LHCII-LHCII interactions have not been extensively studied. Here, we correlated fluorescence lifetime imaging microscopy (FLIM) and atomic force microscopy (AFM) of trimeric LHCII adsorbed to mica substrates and manipulated the environment to cause varying degrees of quenching. AFM showed that LHCII self-assembled onto mica forming 2D-aggregates (25-150 nm width). FLIM determined that LHCII in these aggregates were in a quenched state, with much lower fluorescence lifetimes (~0.25 ns) compared to free LHCII in solution (2.2-3.9 ns). LHCII-LHCII interactions were disrupted by thylakoid lipids or phospholipids, leading to intermediate fluorescent lifetimes (0.6-0.9 ns). To our knowledge, this is the first in vitro correlation of nanoscale membrane imaging with LHCII quenching. Our findings suggest that lipids could play a key role in modulating the extent of LHCII-LHCII interactions within the thylakoid membrane and so the propensity for NPQ activation.
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Affiliation(s)
- Peter G Adams
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK; Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
| | - Cvetelin Vasilev
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Matthew P Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
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Boonen B, Alpizar YA, Meseguer VM, Talavera K. TRP Channels as Sensors of Bacterial Endotoxins. Toxins (Basel) 2018; 10:toxins10080326. [PMID: 30103489 PMCID: PMC6115757 DOI: 10.3390/toxins10080326] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 08/02/2018] [Accepted: 08/08/2018] [Indexed: 02/07/2023] Open
Abstract
The cellular and systemic effects induced by bacterial lipopolysaccharides (LPS) have been solely attributed to the activation of the Toll-like receptor 4 (TLR4) signalling cascade. However, recent studies have shown that LPS activates several members of the Transient Receptor Potential (TRP) family of cation channels. Indeed, LPS induces activation of the broadly-tuned chemosensor TRPA1 in sensory neurons in a TLR4-independent manner, and genetic ablation of this channel reduced mouse pain and inflammatory responses triggered by LPS and the gustatory-mediated avoidance to LPS in fruit flies. LPS was also shown to activate TRPV4 channels in airway epithelial cells, an effect leading to an immediate production of bactericidal nitric oxide and to an increase in ciliary beat frequency. In this review, we discuss the role of TRP channels as sensors of bacterial endotoxins, and therefore, as crucial players in the timely detection of invading gram-negative bacteria.
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Affiliation(s)
- Brett Boonen
- Laboratory for Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, O&N1 Herestraat 49 - box 802, 3000 Leuven, Belgium.
| | - Yeranddy A Alpizar
- Laboratory for Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, O&N1 Herestraat 49 - box 802, 3000 Leuven, Belgium.
| | - Victor M Meseguer
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, 03550 San Juan de Alicante, Spain.
| | - Karel Talavera
- Laboratory for Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, O&N1 Herestraat 49 - box 802, 3000 Leuven, Belgium.
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40
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Zemljič Jokhadar Š, Klančnik U, Grundner M, Švelc Kebe T, Vrhovec Hartman S, Liović M, Derganc J. GPMVs in variable physiological conditions: could they be used for therapy delivery? BMC BIOPHYSICS 2018; 11:1. [PMID: 29308185 PMCID: PMC5751824 DOI: 10.1186/s13628-017-0041-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 12/18/2017] [Indexed: 12/23/2022]
Abstract
Background Cell based carriers are increasingly recognized as a good system for cargo delivery to cells. One of the reasons is their biocompatibility and low toxicity compared to artificial systems. Giant plasma membrane vesicles (GPMV) derive from the cell plasma membrane. Thus they offer the closest approximation to it, which makes them good candidates for potential drug delivery systems. To evaluate the applicability of GPMVs as carriers, we analyzed their basic biophysical properties to test their robustness in the face of changeable physiological conditions, as well as their ability to translocate across the membrane into cells. Results GPMVs formed from human umbilical vein endothelial cells (HUVEC) sustain a drastic osmotic challenge (50-500 mOsmoL/kg) unlike giant unilamelar vesicles (GUVs). In hyper-osmotic solutions the average volume decreases and membrane invaginations form, while in the hypo-osmolar buffer the volume of GPMVs increases and these changes were not reversible. The membranes of flaccid GPMVs started to wrinkle unevenly giving rise to buds after exposure to lipopolysaccharide (LPS). The shape changes in GUVs are reversible in contrast to GPMVs after LPS removal. GPMVs exposed to fluorescent LPS exhibited a signal that remained visible in some GPMVs even after LPS removal, which was never the case with GUVs. Calcein penetrated both into GUVs and GPMVs, however after the removal from the bulk solution some of the GPMVs still exhibited very bright signal, while in GUVs only a weak fluorescent signal was detected. We could also see that practically all GPMVs incorporated dextran initially, but after the dextran solution was changed with the initial non-fluorescent solution it remained only in 20% of them. The majority of HUVEC cells displayed a fluorescent signal after the incubation with GPMVs that contained fluorescently labeled dextran. Conclusion Our findings indicate that GPMVs behave quite differently from artificially made giant phospholipid vesicles and the changes induced by the different treatments we subjected them to are not reversible. We also demonstrate that different substances can be both loaded into them and delivered into cells, so GPMVs may be of potential use as cargo/therapy delivery systems.
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Affiliation(s)
- Špela Zemljič Jokhadar
- Institute of biophysics, Faculty of medicine, University of Ljubljana, Vrazov trg 2, SI-1000 Ljubljana, Slovenia
| | - Urška Klančnik
- Institute of biophysics, Faculty of medicine, University of Ljubljana, Vrazov trg 2, SI-1000 Ljubljana, Slovenia
| | - Maja Grundner
- Institute of biophysics, Faculty of medicine, University of Ljubljana, Vrazov trg 2, SI-1000 Ljubljana, Slovenia
| | - Tjaša Švelc Kebe
- Institute of biophysics, Faculty of medicine, University of Ljubljana, Vrazov trg 2, SI-1000 Ljubljana, Slovenia.,Jožef Stefan Institute, Ljubljana, Slovenia
| | - Saša Vrhovec Hartman
- Institute of biophysics, Faculty of medicine, University of Ljubljana, Vrazov trg 2, SI-1000 Ljubljana, Slovenia
| | - Mirjana Liović
- Institute of biochemistry, Faculty of medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Jure Derganc
- Institute of biophysics, Faculty of medicine, University of Ljubljana, Vrazov trg 2, SI-1000 Ljubljana, Slovenia
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Enhanced capture of bacteria and endotoxin by antimicrobial WLBU2 peptide tethered on polyethylene oxide spacers. Biointerphases 2017; 12:05G603. [DOI: 10.1116/1.4997049] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Colorimetric analysis of lipopolysaccharides based on its self-assembly to inhibit ion transport. Anal Chim Acta 2017; 992:85-93. [DOI: 10.1016/j.aca.2017.09.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 09/02/2017] [Accepted: 09/03/2017] [Indexed: 11/22/2022]
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43
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Assessment of Pasteurella multocida A Lipopolysaccharide, as an Adhesin in an In Vitro Model of Rabbit Respiratory Epithelium. Vet Med Int 2017; 2017:8967618. [PMID: 28251016 PMCID: PMC5303596 DOI: 10.1155/2017/8967618] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 12/06/2016] [Accepted: 12/29/2016] [Indexed: 11/18/2022] Open
Abstract
The role of the P. multocida lipopolysaccharide (LPS) as a putative adhesin during the early stages of infection with this bacterium in the respiratory epithelium of rabbits was investigated. By light microscopy and double enzyme labeling of nasal septa tissues, the amount of bacteria attached to the respiratory epithelium and the amount of LPS present in goblet cells at different experimental times were estimated. Transmission electron microscopy (TEM) and LPS labeling with colloidal gold particles were also used to determine the exact location of LPS in the cells. Septa that were challenged with LPS of P. multocida and 30 minutes later with P. multocida showed more adherent bacteria and more severe lesions than the other treatments. Free LPS was observed in the lumen of the nasal septum, forming bilamellar structures and adhering to the cilia, microvilli, cytoplasmic membrane, and cytoplasm of epithelial ciliated and goblet cells. The above findings suggest that P. multocida LPS plays an important role in the process of bacterial adhesion and that it has the ability of being internalized into host cells.
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Kalita P, Chaturvedula LM, Sritharan V, Gupta S. In vitro flow-through assay for rapid detection of endotoxin in human sera: A proof-of-concept. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2017; 13:1483-1490. [PMID: 28131882 DOI: 10.1016/j.nano.2017.01.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 12/20/2016] [Accepted: 01/13/2017] [Indexed: 10/20/2022]
Abstract
An increase in endotoxin concentration in the bloodstream can trigger activation of innate immune response leading to septic shock. There is currently no method available for rapid endotoxin detection at a patient's bedside. We demonstrate a simple, portable and cost-effective strategy to measure endotoxin levels in human serum within 5min using a flow-through assay. A drop of serum containing LPS was spotted on an endotoxin-affinity membrane placed over high-wicking absorbent pads. Subsequent addition of polymyxin B sulfate drug-conjugated gold nanoparticles allowed concentration-dependent visualization of spots by the naked eye in the clinically-relevant range of 10pg/mL to 10ng/mL. The results were quantified using a concentration-calibrated color chart and the assay performance was tested with archival plasma samples of 18 known septicemia patients. The results showed a reasonably good correlation with the patients' hematological data. This proof-of-concept study puts forth an interesting alternative for early septicemia diagnosis in future.
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Affiliation(s)
- Prasanta Kalita
- Department of Chemical Engineering, Indian Institute of Technology Delhi, Hauz Khas, India
| | - Lakshmi M Chaturvedula
- Molecular Diagnostics & Biomarkers Laboratory, Global Medical Education and Research Foundation, Hyderabad, India
| | - Venkataraman Sritharan
- Molecular Diagnostics & Biomarkers Laboratory, Global Medical Education and Research Foundation, Hyderabad, India
| | - Shalini Gupta
- Department of Chemical Engineering, Indian Institute of Technology Delhi, Hauz Khas, India.
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Gräb O, Abacilar M, Daus F, Geyer A, Steinem C. 3D-Membrane Stacks on Supported Membranes Composed of Diatom Lipids Induced by Long-Chain Polyamines. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:10144-10152. [PMID: 27603681 DOI: 10.1021/acs.langmuir.6b02575] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Long-chain polyamines (LCPAs) are intimately involved in the biomineralization process of diatoms taking place in silica deposition vesicles being acidic compartments surrounded by a lipid bilayer. Here, we addressed the question whether and how LCPAs interact with lipid membranes composed of glycerophospholipids and glyceroglycolipids mimicking the membranes of diatoms and higher plants. Solid supported lipid bilayers and monolayers containing the three major components that are unique in diatoms and higher plants, i.e., monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), and sulfoquinovosyldiacylglycerol (SQDG), were prepared by spreading small unilamellar vesicles. The integrity of the membranes was investigated by fluorescence microscopy and atomic force microscopy showing continuous flat bilayers and monolayers with small protrusions on top of the membrane. The addition of a synthetic polyamine composed of 13 amine groups separated by a propyl spacer (C3N13) results in flat but three-dimensional membrane stacks within minutes. The membrane stacks are connected with the underlying membrane as verified by fluorescence recovery after photobleaching experiments. Membrane stack formation was found to be independent of the lipid composition; i.e., neither glyceroglycolipids nor negatively charged lipids were required. However, the formation process was strongly dependent on the chain length of the polyamine. Whereas short polyamines such as the naturally occurring spermidine, spermine, and the synthetic polyamines C3N4 and C3N5 do not induce stack formation, those containing seven and more amine groups (C3N7, C3N13, and C3N18) do form membrane stacks. The observed stack formation might have implications for the stability and expansion of the silica deposition vesicle during valve and girdle band formation in diatoms.
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Affiliation(s)
- Oliver Gräb
- Institute of Organic and Biomolecular Chemistry, University of Göttingen , Tammannstr. 2, 37077 Göttingen, Germany
| | - Maryna Abacilar
- Faculty of Chemistry, Philipps-University Marburg , Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Fabian Daus
- Faculty of Chemistry, Philipps-University Marburg , Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Armin Geyer
- Faculty of Chemistry, Philipps-University Marburg , Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Claudia Steinem
- Institute of Organic and Biomolecular Chemistry, University of Göttingen , Tammannstr. 2, 37077 Göttingen, Germany
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Stromberg LR, Hengartner NW, Swingle KL, Moxley RA, Graves SW, Montaño GA, Mukundan H. Membrane Insertion for the Detection of Lipopolysaccharides: Exploring the Dynamics of Amphiphile-in-Lipid Assays. PLoS One 2016; 11:e0156295. [PMID: 27227979 PMCID: PMC4881986 DOI: 10.1371/journal.pone.0156295] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 05/12/2016] [Indexed: 12/27/2022] Open
Abstract
Shiga toxin-producing Escherichia coli is an important cause of foodborne illness, with cases attributable to beef, fresh produce and other sources. Many serotypes of the pathogen cause disease, and differentiating one serotype from another requires specific identification of the O antigen located on the lipopolysaccharide (LPS) molecule. The amphiphilic structure of LPS poses a challenge when using classical detection methods, which do not take into account its lipoglycan biochemistry. Typically, detection of LPS requires heat or chemical treatment of samples and relies on bioactivity assays for the conserved lipid A portion of the molecule. Our goal was to develop assays to facilitate the direct and discriminative detection of the entire LPS molecule and its O antigen in complex matrices using minimal sample processing. To perform serogroup identification of LPS, we used a method called membrane insertion on a waveguide biosensor, and tested three serogroups of LPS. The membrane insertion technique allows for the hydrophobic association of LPS with a lipid bilayer, where the exposed O antigen can be targeted for specific detection. Samples of beef lysate were spiked with LPS to perform O antigen specific detection of LPS from E. coli O157. To validate assay performance, we evaluated the biophysical interactions of LPS with lipid bilayers both in- and outside of a flow cell using fluorescence microscopy and fluorescently doped lipids. Our results indicate that membrane insertion allows for the qualitative and reliable identification of amphiphilic LPS in complex samples like beef homogenates. We also demonstrated that LPS-induced hole formation does not occur under the conditions of the membrane insertion assays. Together, these findings describe for the first time the serogroup-specific detection of amphiphilic LPS in complex samples using a membrane insertion assay, and highlight the importance of LPS molecular conformations in detection architectures.
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Affiliation(s)
- Loreen R. Stromberg
- Center for Biomedical Engineering, University of New Mexico, Albuquerque, New Mexico, United States of America
- Physical Chemistry and Applied Spectroscopy, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
- The New Mexico Consortium, Los Alamos, New Mexico, United States of America
| | - Nicolas W. Hengartner
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Kirstie L. Swingle
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Rodney A. Moxley
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Steven W. Graves
- Center for Biomedical Engineering, University of New Mexico, Albuquerque, New Mexico, United States of America
- The New Mexico Consortium, Los Alamos, New Mexico, United States of America
| | - Gabriel A. Montaño
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Harshini Mukundan
- Center for Biomedical Engineering, University of New Mexico, Albuquerque, New Mexico, United States of America
- Physical Chemistry and Applied Spectroscopy, Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
- The New Mexico Consortium, Los Alamos, New Mexico, United States of America
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Kataoka-Hamai C, Kaizuka Y, Taguchi T. Binding of Lipopolysaccharide and Cholesterol-Modified Gelatin on Supported Lipid Bilayers: Effect of Bilayer Area Confinement and Bilayer Edge Tension. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:1250-1258. [PMID: 26735125 DOI: 10.1021/acs.langmuir.5b04302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Binding of amphiphilic molecules to supported lipid bilayers (SLBs) often results in lipid fibril extension from the SLBs. Previous studies proposed that amphiphiles with large and flexible hydrophilic regions trigger lipid fibril formation in SLBs by inducing membrane curvature via their hydrophilic regions. However, no experimental studies have verified this mechanism of fibril formation. In this work, we investigated the binding of lipopolysaccharide (LPS) and cholesterol-modified gelatin to SLBs using fluorescence microscopy. SLBs with restricted and unrestricted bilayer areas were employed to identify the mechanism of fibril generation. We show that the main cause of lipid fibril formation is an approximately 20% expansion in the bilayer area rather than increased membrane curvature. The data indicate that bilayer area confinement plays a critical role in morphological changes of SLBs even when bound amphiphilic molecules have a large hydrophilic domain. We also show that bilayer area change after LPS insertion is dependent on the patch shape of the SLB. When an SLB patch consists of a broad bilayer segment connected to a long thin streak, bilayer area expansion mainly occurs within the bilayer streak. The results indicate that LPS insertion causes net lipid flow from the broad bilayer region to the streak area. The differential increase in area is explained by the instability of planar bilayer streaks that originate from the large energetic contribution of line tension arising along the bilayer edge.
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Affiliation(s)
- Chiho Kataoka-Hamai
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Yoshihisa Kaizuka
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science , 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Tetsushi Taguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
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Luo YH, Wu ZW, Tsai HT, Lin SY, Lin P. Endotoxin Nanovesicles: Hydrophilic Gold Nanodots Control Supramolecular Lipopolysaccharide Assembly for Modulating Immunological Responses. NANO LETTERS 2015; 15:6446-6453. [PMID: 26339979 DOI: 10.1021/acs.nanolett.5b01809] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this study, we sought to control the assembly of an endotoxin known as the biologically supramolecular lipopolysaccharide (LPS, which consists of three portions: an O antigen, a core carbohydrate, and a lipid A molecule) in order to modulate immunological responses in a manner that has the potential for utilization in vaccine development. Changing the structures of LPS aggregates from lamellas to specific nonlamellas (i.e., cubosomes and hexosomes) can dramatically enhance the strength of LPS in causing inflammatory responses, leading to highly active responses. In order to control the formation of cubosome-free and hexosome-free nonlamellas, we designed a simple strategy based on the use of hydrophilic gold nanodots (AuNDs) to control LPS assembly to facilitate the formation of stable endotoxin nanovesicles, which are stable precursors of cubosomes and hexosomes with specific immunological effects. Structurally, the wall thicknesses of these nanovesicles are exactly twice the lengths of a single LPS molecule, indicating that the LPS molecules adopt a tail-to-tail arrangement (with the lipid A portions acting as the tail domain). The involvement of the hydrophilic AuNDs to laterally link polar domains of LPS can result in the progressive extension of an endotoxically active zone of lipid A assembly, leading to the eventual formation of large-size nanovesicles. Our results showed that endotoxin nanovesicles with such dense lipid A units can elicit the stronger inflammatory gene expressions, including interleukin 6 (IL-6), IL-1A, TNF-α, C-X-C chemokine ligand (CXCL) 1, 2, and 11, which have characteristics of T-helper 1 adjuvants. These findings provide evidence that the concept of manipulating the surface hydrophilicity of AuNDs to control LPS assembly in order to avoid the formation of highly active cubosomes and hexosomes, and thereby modulate immunological responses appropriately, could prove useful in vaccine development.
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Affiliation(s)
- Yueh-Hsia Luo
- National Institute of Environmental Health Sciences and ‡Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes , Zhunan, Taiwan
| | - Zong Wei Wu
- National Institute of Environmental Health Sciences and ‡Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes , Zhunan, Taiwan
| | - Hui-Ti Tsai
- National Institute of Environmental Health Sciences and ‡Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes , Zhunan, Taiwan
| | - Shu-Yi Lin
- National Institute of Environmental Health Sciences and ‡Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes , Zhunan, Taiwan
| | - Pinpin Lin
- National Institute of Environmental Health Sciences and ‡Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes , Zhunan, Taiwan
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Exploiting lipopolysaccharide-induced deformation of lipid bilayers to modify membrane composition and generate two-dimensional geometric membrane array patterns. Sci Rep 2015; 5:10331. [PMID: 26015293 PMCID: PMC4444833 DOI: 10.1038/srep10331] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 04/08/2015] [Indexed: 12/31/2022] Open
Abstract
Supported lipid bilayers have proven effective as model membranes for investigating biophysical processes and in development of sensor and array technologies. The ability to modify lipid bilayers after their formation and in situ could greatly advance membrane technologies, but is difficult via current state-of-the-art technologies. Here we demonstrate a novel method that allows the controlled post-formation processing and modification of complex supported lipid bilayer arrangements, under aqueous conditions. We exploit the destabilization effect of lipopolysaccharide, an amphiphilic biomolecule, interacting with lipid bilayers to generate voids that can be backfilled to introduce desired membrane components. We further demonstrate that when used in combination with a single, traditional soft lithography process, it is possible to generate hierarchically-organized membrane domains and microscale 2-D array patterns of domains. Significantly, this technique can be used to repeatedly modify membranes allowing iterative control over membrane composition. This approach expands our toolkit for functional membrane design, with potential applications for enhanced materials templating, biosensing and investigating lipid-membrane processes.
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