1
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Yang H, O’Keefe I, Smith RD, Sumner KP, Sherman ME, Goodlett DR, Sweet CR, Ernst RK. A Multimodal System for Lipid A Structural Analysis from a Single Colony. Anal Chem 2024; 96. [PMID: 39149983 PMCID: PMC11359392 DOI: 10.1021/acs.analchem.4c01566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 08/02/2024] [Accepted: 08/05/2024] [Indexed: 08/17/2024]
Abstract
Structural elucidation of Gram-negative bacterial lipid A traditionally requires chemical extraction followed by tandem MS data in the negative ion mode. Previously, we reported FLAT and FLATn as methods to rapidly determine the structure of lipid A without chromatographic techniques. In this work, we extend the capability and effectiveness of these techniques to elucidate the chemical structure in a de novo manner by including the use of positive ion mode (FLAT+ and FLATn+) spectral approaches. Advantages of positive mode analysis of lipid A include the generation of more interpretable and informative fragmentation patterns that include the identification of diagnostic fragments, including selective dissociation of a glycosidic bond between two glucosamine units and the selective dissociation at the secondary acyl chain in 2'-N, allowing for the determination of the composition of fatty acids. As a proof of principle, we present here two previously uncharacterized structures of lipid A from Roseomonas mucosa (R. mucosa) and Moraxella canis (M. canis). In R. mucosa, we determined the lipid A structure with a nonconventional backbone of-β-1,6 linked 2,3-dideoxy-2,3-diamno-d-glucopyranose further modified with galacturonic acid in the place of typical 1-phosphate, and in M. canis, we assigned a single discrete structure using the specific fragmentation patterns of terminal phosphate groups present in lipid A. Therefore, FLATn+, in combination with FLAT and FLATn, provides a multimodal structural platform for rapid structure characterization of unusual and complex lipid A structures from a single colony.
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Affiliation(s)
- Hyojik Yang
- Department
of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland 21201, United States
| | - Ian O’Keefe
- Department
of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland 21201, United States
| | - Richard D. Smith
- Department
of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland 21201, United States
- Department
of Pathology, School of Medicine, University
of Maryland, Baltimore, Maryland 21201, United
States
| | - Kylie P. Sumner
- Department
of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland 21201, United States
| | - Matthew E. Sherman
- Department
of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland 21201, United States
| | - David R. Goodlett
- Department
of Biochemistry and Microbiology, University
of Victoria, Victoria, British Columbia V8P 5C2, Canada
- Genome
British Columbia Proteomics Centre, University
of Victoria, Victoria, British Columbia V8Z 7Z8, Canada
| | - Charles R. Sweet
- Chemistry
Department, United States Naval Academy, Annapolis, Maryland 21402, United States
| | - Robert K. Ernst
- Department
of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland 21201, United States
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2
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Dörnyei Á, Kilár A, Sándor V. Identification of a Chimera Mass Spectrum of Isomeric Lipid A Species Using Negative Ion Tandem Mass Spectrometry. Toxins (Basel) 2024; 16:322. [PMID: 39057962 PMCID: PMC11281664 DOI: 10.3390/toxins16070322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Revised: 07/12/2024] [Accepted: 07/16/2024] [Indexed: 07/28/2024] Open
Abstract
The toxic nature of bacterial endotoxins is affected by the structural details of lipid A, including the variety and position of acyl chains and phosphate group(s) on its diglucosamine backbone. Negative-ion mode tandem mass spectrometry is a primary method for the structure elucidation of lipid A, used independently or in combination with separation techniques. However, it is challenging to accurately characterize constitutional isomers of lipid A extracts by direct mass spectrometry, as the elemental composition and molecular mass of these molecules are identical. Thus, their simultaneous fragmentation leads to a composite, so-called chimera mass spectrum. The present study focuses on the phosphopositional isomers of the classical monophosphorylated, hexaacylated Escherichia coli-type lipid A. Collision-induced dissociation (CID) was performed in an HPLC-ESI-QTOF system. Energy-resolved mass spectrometry (ERMS) was applied to uncover the distinct fragmentation profiles of the phosphorylation isomers. A fragmentation strategy applying multi-levels of collision energy has been proposed and applied to reveal sample complexity, whether it contains only a 4'-phosphorylated species or a mixture of 1- and 4'-phosphorylated variants. This comparative fragmentation study of isomeric lipid A species demonstrates the high potential of ERMS-derived information for the successful discrimination of co-ionized phosphorylation isomers of hexaacylated lipid A.
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Affiliation(s)
- Ágnes Dörnyei
- Department of Analytical and Environmental Chemistry and Szentágothai Research Centre, Faculty of Sciences, University of Pécs, Ifjúság útja 6., H-7624 Pécs, Hungary
| | - Anikó Kilár
- Institute of Bioanalysis, Medical School, University of Pécs, Szigeti út 12., H-7624 Pécs, Hungary; (A.K.); (V.S.)
| | - Viktor Sándor
- Institute of Bioanalysis, Medical School, University of Pécs, Szigeti út 12., H-7624 Pécs, Hungary; (A.K.); (V.S.)
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3
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Huang D, Chen L, Wang Y, Wang Z, Wang J, Wang X. Characterization of a secondary hydroxy-acyltransferase for lipid A in Vibrio parahaemolyticus. Microbiol Res 2024; 283:127712. [PMID: 38593580 DOI: 10.1016/j.micres.2024.127712] [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: 01/10/2024] [Revised: 03/22/2024] [Accepted: 04/03/2024] [Indexed: 04/11/2024]
Abstract
Lipid A plays a crucial role in Vibrio parahaemolyticus. Previously we have reported the diversity of secondary acylation of lipid A in V. parahaemolyticus and four V. parahaemolyticus genes VP_RS08405, VP_RS01045, VP_RS12170, and VP_RS00880 exhibiting homology to the secondary acyltransferases in Escherichia coli. In this study, the gene VP_RS12170 was identified as a specific lipid A secondary hydroxy-acyltransferase responsible for transferring a 3-hydroxymyristate to the 2'-position of lipid A. Four E. coli mutant strains WHL00, WHM00, WH300, and WH001 were constructed, and they would synthesize lipid A with different structures due to the absence of genes encoding lipid A secondary acyltransferases or Kdo transferase. Then V. parahaemolyticus VP_RS12170 was overexpressed in W3110, WHL00, WHM00, WH300, and WH001, and lipid A was isolated from these strains and analyzed by using thin-layer chromatography and high-performance liquid chromatography-tandem mass spectrometry. The detailed structural changes of lipid A in these mutant strains with and without VP_RS12170 overexpression were compared and conclude that VP_RS12170 can specifically transfer a 3-hydroxymyristate to the 2'-position of lipid A. This study also demonstrated that the function of VP_RS12170 is Kdo-dependent and its favorite substrate is Kdo-lipid IVA. These findings give us better understanding the biosynthetic pathway and the structural diversity of V. parahaemolyticus lipid A.
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Affiliation(s)
- Danyang Huang
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Lingyan Chen
- School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yang Wang
- School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Zhe Wang
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Jianli Wang
- School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xiaoyuan Wang
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Biotechnology, Jiangnan University, Wuxi 214122, China.
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4
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Fux AC, Casonato Melo C, Michelini S, Swartzwelter BJ, Neusch A, Italiani P, Himly M. Heterogeneity of Lipopolysaccharide as Source of Variability in Bioassays and LPS-Binding Proteins as Remedy. Int J Mol Sci 2023; 24:ijms24098395. [PMID: 37176105 PMCID: PMC10179214 DOI: 10.3390/ijms24098395] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 05/03/2023] [Accepted: 05/05/2023] [Indexed: 05/15/2023] Open
Abstract
Lipopolysaccharide (LPS), also referred to as endotoxin, is the major component of Gram-negative bacteria's outer cell wall. It is one of the main types of pathogen-associated molecular patterns (PAMPs) that are known to elicit severe immune reactions in the event of a pathogen trespassing the epithelial barrier and reaching the bloodstream. Associated symptoms include fever and septic shock, which in severe cases, might even lead to death. Thus, the detection of LPS in medical devices and injectable pharmaceuticals is of utmost importance. However, the term LPS does not describe one single molecule but a diverse class of molecules sharing one common feature: their characteristic chemical structure. Each bacterial species has its own pool of LPS molecules varying in their chemical composition and enabling the aggregation into different supramolecular structures upon release from the bacterial cell wall. As this heterogeneity has consequences for bioassays, we aim to examine the great variability of LPS molecules and their potential to form various supramolecular structures. Furthermore, we describe current LPS quantification methods and the LPS-dependent inflammatory pathway and show how LPS heterogeneity can affect them. With the intent of overcoming these challenges and moving towards a universal approach for targeting LPS, we review current studies concerning LPS-specific binders. Finally, we give perspectives for LPS research and the use of LPS-binding molecules.
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Affiliation(s)
- Alexandra C Fux
- Division of Allergy & Immunology, Department of Biosciences & Medical Biology, Paris Lodron University of Salzburg (PLUS), Hellbrunnerstraße 34, 5020 Salzburg, Austria
- Chemical Biology Department, R&D Reagents, Miltenyi Biotec B.V. & Co. KG, Friedrich-Ebert-Straße 68, 51429 Bergisch Gladbach, Germany
| | - Cristiane Casonato Melo
- Division of Allergy & Immunology, Department of Biosciences & Medical Biology, Paris Lodron University of Salzburg (PLUS), Hellbrunnerstraße 34, 5020 Salzburg, Austria
- Chemical Biology Department, R&D Reagents, Miltenyi Biotec B.V. & Co. KG, Friedrich-Ebert-Straße 68, 51429 Bergisch Gladbach, Germany
| | - Sara Michelini
- Biotechnical Faculty, Department of Biology, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia
| | - Benjamin J Swartzwelter
- Department of Microbiology, Immunology, and Pathology, 1601 Campus Delivery, Colorado State University, Fort Collins, CO 80523, USA
| | - Andreas Neusch
- Experimental Medical Physics, Heinrich-Heine University Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Paola Italiani
- Institute of Biochemistry and Cell Biology, Consiglio Nazionale delle Ricerche (CNR), Via P. Castellino 111, 80131 Naples, Italy
- Stazione Zoologica Anton Dohrn (SZN), Villa Comunale, 80121 Naples, Italy
| | - Martin Himly
- Division of Allergy & Immunology, Department of Biosciences & Medical Biology, Paris Lodron University of Salzburg (PLUS), Hellbrunnerstraße 34, 5020 Salzburg, Austria
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5
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Aissa I, Dörnyei Á, Sándor V, Kilár A. Complete Structural Elucidation of Monophosphorylated Lipid A by CID Fragmentation of Protonated Molecule and Singly Charged Sodiated Adducts. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:92-100. [PMID: 36539922 PMCID: PMC9817073 DOI: 10.1021/jasms.2c00269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 12/02/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
Lipid A, the inflammatory portion of lipopolysaccharides (LPS, endotoxins), is the main component of the outer membrane of Gram-negative bacteria. Its bioactivity in humans and animals is strictly related to its chemical structure. In the present work, the fragmentation patterns of the singly charged monosodium [M + Na]+ and disodium [M - H + 2Na]+ adducts, as well as the protonated form of monophosphorylated lipid A species were investigated in detail using positive-ion electrospray ionization-based tandem (MS/MS) and multistage mass spectrometry (MSn) with low-energy collision-induced dissociation (CID). Several synthetic and native lipid A samples were included in the study. We found that the fragmentation pattern of disodiated lipid A is quite similar to that of the well-characterized deprotonated lipid A molecule (typically detected in the negative-ion mode), while the fragmentation pattern of monosodiated lipid A contains fragment ions similar to those of both protonated and deprotonated lipid A molecules. In summary, we propose a new mass spectrometry approach based on the fragmentation regularities of only positively charged precursor ions to dissect the location of the phosphate group and fatty acid moieties on monophosphorylated lipid A. Moreover, this study provides a better understanding of the so-called "chimera mass spectra", which are commonly detected during the fragmentation of native lipid A samples containing both C-1 and C-4' phosphate positional isomers but rarely identified in negative-ion mode.
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Affiliation(s)
- Ibrahim Aissa
- Department
of Analytical and Environmental Chemistry, Faculty of Sciences, University of Pécs, Ifjúság útja 6, H-7624 Pécs, Hungary
| | - Ágnes Dörnyei
- Department
of Analytical and Environmental Chemistry, Faculty of Sciences, University of Pécs, Ifjúság útja 6, H-7624 Pécs, Hungary
| | - Viktor Sándor
- Institute
of Bioanalysis, Medical School and Szentágothai Research Centre, University of Pécs, Szigeti út 12, H-7624 Pécs, Hungary
| | - Anikó Kilár
- Institute
of Bioanalysis, Medical School and Szentágothai Research Centre, University of Pécs, Szigeti út 12, H-7624 Pécs, Hungary
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6
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Nyholm SV, McFall-Ngai MJ. A lasting symbiosis: how the Hawaiian bobtail squid finds and keeps its bioluminescent bacterial partner. Nat Rev Microbiol 2021; 19:666-679. [PMID: 34089010 PMCID: PMC8440403 DOI: 10.1038/s41579-021-00567-y] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2021] [Indexed: 01/08/2023]
Abstract
For more than 30 years, the association between the Hawaiian bobtail squid, Euprymna scolopes, and the bioluminescent bacterium Vibrio fischeri has been studied as a model system for understanding the colonization of animal epithelia by symbiotic bacteria. The squid-vibrio light-organ system provides the exquisite resolution only possible with the study of a binary partnership. The impact of this relationship on the partners' biology has been broadly characterized, including their ecology and evolutionary biology as well as the underlying molecular mechanisms of symbiotic dynamics. Much has been learned about the factors that foster initial light-organ colonization, and more recently about the maturation and long-term maintenance of the association. This Review synthesizes the results of recent research on the light-organ association and also describes the development of new horizons for E. scolopes as a model organism that promises to inform biology and biomedicine about the basic nature of host-microorganism interactions.
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Affiliation(s)
- Spencer V Nyholm
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA.
| | - Margaret J McFall-Ngai
- Pacific Biosciences Research Center, Kewalo Marine Laboratory, University of Hawai'i at Mānoa, Honolulu, HI, USA.
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7
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Lin TL, Shu CC, Chen YM, Lu JJ, Wu TS, Lai WF, Tzeng CM, Lai HC, Lu CC. Like Cures Like: Pharmacological Activity of Anti-Inflammatory Lipopolysaccharides From Gut Microbiome. Front Pharmacol 2020; 11:554. [PMID: 32425790 PMCID: PMC7212368 DOI: 10.3389/fphar.2020.00554] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 04/14/2020] [Indexed: 12/13/2022] Open
Abstract
Gut microbiome maintains local gut integrity and systemic host homeostasis, where optimal control of intestinal lipopolysaccharides (LPS) activity may play an important role. LPS mainly produced from gut microbiota are a group of lipid-polysaccharide chemical complexes existing in the outer membrane of Gram-negative bacteria. Traditionally, LPS mostly produced from Proteobacteria are well known for their ability in inducing strong inflammatory responses (proinflammatory LPS, abbreviated as P-LPS), leading to septic shock or even death in animals and humans. Although the basic structures and chemical properties of P-LPS derived from different bacterial species generally show similarity, subtle and differential immune activation activities are observed. On the other hand, frequently ignored, a group of LPS molecules mainly produced by certain microbiota bacteria such as Bacteroidetes show blunt or even antagonistic activity in initiating pro-inflammatory responses (anti-inflammatory LPS, abbreviated as A-LPS). In this review, besides the immune activation properties of P-LPS, we also focus on the description of anti-inflammatory effects of A-LPS, and their potential antagonistic mechanism. We address the possibility of using native or engineered A-LPS for immune modulation in prevention or even treatment of P-LPS induced chronic inflammation related diseases. Understanding the exquisite interactive relationship between structure-activity correlation of P- and A-LPS not only contributes to molecular understanding of immunomodulation and homeostasis, but also re-animates the development of novel LPS-based pharmacological strategy for prevention and therapy of chronic inflammation related diseases.
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Affiliation(s)
- Tzu-Lung Lin
- Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Microbiota Research Center and Emerging Viral Infections Research Center, Chang Gung University, Taoyuan, Taiwan
| | - Chin-Chung Shu
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Young-Mao Chen
- Bachelor Degree Program in Marine Biotechnology, College of Life Sciences, National Taiwan Ocean University, Keelung, Taiwan
| | - Jang-Jih Lu
- Department of Laboratory Medicine, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Ting-Shu Wu
- Division of Infectious Diseases, Department of Internal Medicine, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Wei-Fan Lai
- Department of Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chi-Meng Tzeng
- School of Pharmaceutical Sciences, Xiamen University, Xiamen, China
| | - Hsin-Chih Lai
- Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Microbiota Research Center and Emerging Viral Infections Research Center, Chang Gung University, Taoyuan, Taiwan.,Central Research Laboratory, Xiamen Chang Gung Allergology Consortium, Xiamen Chang Gung Hospital, Xiamen, China.,Research Center for Chinese Herbal Medicine and Research Center for Food and Cosmetic Safety, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan, Taiwan
| | - Chia-Chen Lu
- Department of Chest Medicine, Internal Medicine, Fu Jen Catholic University Hospital, Fu Jen Catholic University, New Taipei City, Taiwan.,Department of Respiratory Therapy, Fu Jen Catholic University, New Taipei City, Taiwan
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8
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Tawab A, Akbar N, Hasssan M, Habib F, Ali A, Rahman M, Jabbar A, Rauf W, Iqbal M. Mass spectrometric analysis of lipid A obtained from the lipopolysaccharide ofPasteurella multocida. RSC Adv 2020; 10:30917-30933. [PMID: 35516050 PMCID: PMC9056370 DOI: 10.1039/d0ra05463a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/06/2020] [Indexed: 01/14/2023] Open
Abstract
LC/MS-based variant profiling of lipid A component of endotoxic lipopolysaccharides ofPasteurella multocidatype B:2, a causative agent of haemorrhagic septicaemia in water buffalo and cattle.
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Affiliation(s)
- Abdul Tawab
- Health Biotechnology Division
- National Institute for Biotechnology and Genetic Engineering (NIBGE)
- Faisalabad-38000
- Pakistan
- Department of Biotechnology NIBGE
| | - Noor Akbar
- Health Biotechnology Division
- National Institute for Biotechnology and Genetic Engineering (NIBGE)
- Faisalabad-38000
- Pakistan
| | - Mujtaba Hasssan
- Health Biotechnology Division
- National Institute for Biotechnology and Genetic Engineering (NIBGE)
- Faisalabad-38000
- Pakistan
| | - Fazale Habib
- Health Biotechnology Division
- National Institute for Biotechnology and Genetic Engineering (NIBGE)
- Faisalabad-38000
- Pakistan
| | - Aamir Ali
- Health Biotechnology Division
- National Institute for Biotechnology and Genetic Engineering (NIBGE)
- Faisalabad-38000
- Pakistan
| | - Moazur Rahman
- Health Biotechnology Division
- National Institute for Biotechnology and Genetic Engineering (NIBGE)
- Faisalabad-38000
- Pakistan
- School of Biological Sciences
| | - Abdul Jabbar
- Health Biotechnology Division
- National Institute for Biotechnology and Genetic Engineering (NIBGE)
- Faisalabad-38000
- Pakistan
- Department of Biotechnology
| | - Waqar Rauf
- Health Biotechnology Division
- National Institute for Biotechnology and Genetic Engineering (NIBGE)
- Faisalabad-38000
- Pakistan
| | - Mazhar Iqbal
- Health Biotechnology Division
- National Institute for Biotechnology and Genetic Engineering (NIBGE)
- Faisalabad-38000
- Pakistan
- Department of Biotechnology NIBGE
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9
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Schwartzman JA, Lynch JB, Ramos SF, Zhou L, Apicella MA, Yew JY, Ruby EG. Acidic pH promotes lipopolysaccharide modification and alters colonization in a bacteria-animal mutualism. Mol Microbiol 2019; 112:1326-1338. [PMID: 31400167 PMCID: PMC6823639 DOI: 10.1111/mmi.14365] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/07/2019] [Indexed: 02/06/2023]
Abstract
Environmental pH can be an important cue for symbiotic bacteria as they colonize their eukaryotic hosts. Using the model mutualism between the marine bacterium Vibrio fischeri and the Hawaiian bobtail squid, we characterized the bacterial transcriptional response to acidic pH experienced during the shift from planktonic to host-associated lifestyles. We found several genes involved in outer membrane structure were differentially expressed based on pH, indicating alterations in membrane physiology as V. fischeri initiates its symbiotic program. Exposure to host-like pH increased the resistance of V. fischeri to the cationic antimicrobial peptide polymixin B, which resembles antibacterial molecules that are produced by the squid to select V. fischeri from the ocean microbiota. Using a forward genetic screen, we identified a homolog of eptA, a predicted phosphoethanolamine transferase, as critical for antimicrobial defense. We used MALDI-MS to verify eptA as an ethanolamine transferase for the lipid-A portion of V. fischeri lipopolysaccharide. We then used a DNA pulldown approach to discover that eptA transcription is activated by the global regulator H-NS. Finally, we revealed that eptA promotes successful squid colonization by V. fischeri, supporting its potential role in initiation of this highly specific symbiosis.
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Affiliation(s)
- Julia A. Schwartzman
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison WI, USA
| | - Jonathan B. Lynch
- Pacific Biosciences Research Center, University of Hawaii-Manoa, Honolulu HI, USA
| | | | - Lawrence Zhou
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison WI, USA
| | - Michael A. Apicella
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City IA, USA
| | - Joanne Y. Yew
- Pacific Biosciences Research Center, University of Hawaii-Manoa, Honolulu HI, USA
| | - Edward G. Ruby
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison WI, USA
- Pacific Biosciences Research Center, University of Hawaii-Manoa, Honolulu HI, USA
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10
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2-Hydroxylation of Acinetobacter baumannii Lipid A Contributes to Virulence. Infect Immun 2019; 87:IAI.00066-19. [PMID: 30745327 PMCID: PMC6434125 DOI: 10.1128/iai.00066-19] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 01/30/2019] [Indexed: 12/15/2022] Open
Abstract
Acinetobacter baumannii causes a wide range of nosocomial infections. This pathogen is considered a threat to human health due to the increasingly frequent isolation of multidrug-resistant strains. Acinetobacter baumannii causes a wide range of nosocomial infections. This pathogen is considered a threat to human health due to the increasingly frequent isolation of multidrug-resistant strains. There is a major gap in knowledge on the infection biology of A. baumannii, and only a few virulence factors have been characterized, including lipopolysaccharide. The lipid A expressed by A. baumannii is hepta-acylated and contains 2-hydroxylaurate. The late acyltransferases controlling the acylation of lipid A have been already characterized. Here, we report the characterization of A. baumannii LpxO, which encodes the enzyme responsible for the 2-hydroxylation of lipid A. By genetic methods and mass spectrometry, we demonstrate that LpxO catalyzes the 2-hydroxylation of the laurate transferred by A. baumannii LpxL. LpxO-dependent lipid A 2-hydroxylation protects A. baumannii from polymyxin B, colistin, and human β-defensin 3. LpxO contributes to the survival of A. baumannii in human whole blood and is required for pathogen survival in the waxmoth Galleria mellonella. LpxO also protects Acinetobacter from G. mellonella antimicrobial peptides and limits their expression. Further demonstrating the importance of LpxO-dependent modification in immune evasion, 2-hydroxylation of lipid A limits the activation of the mitogen-activated protein kinase Jun N-terminal protein kinase to attenuate inflammatory responses. In addition, LpxO-controlled lipid A modification mediates the production of the anti-inflammatory cytokine interleukin-10 (IL-10) via the activation of the transcriptional factor CREB. IL-10 in turn limits the production of inflammatory cytokines following A. baumannii infection. Altogether, our studies suggest that LpxO is a candidate for the development of anti-A. baumannii drugs.
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11
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Martins N, Pereira JL, Antunes FE, Melro E, Duarte CMG, Dias L, Soares AMVM, Lopes I. Role of surfactant headgroups on the toxicity of SLE nS-LAS mixed micelles: A case study using microtox test. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 643:1366-1372. [PMID: 30189553 DOI: 10.1016/j.scitotenv.2018.06.293] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 06/22/2018] [Accepted: 06/24/2018] [Indexed: 06/08/2023]
Abstract
Mixtures containing ether sulfate based surfactants (SLEnS) and linear alkylbenzene sulfonic acid (LAS) are relatively common in personal care and household products. When in mixture, they form mixed micelles, which act as reservoirs for the cleaning process. The increase of ethylene oxide (EO) units in the head of SLEnS lowers the critical micelle concentration, meaning that less quantity of each surfactant is needed to form the micelles. Within an eco-friendly perspective this is advantageous since less chemicals are expected to be released into the environment. But, this advantage will only be effective if variations with the higher number of EO units exhibit a lower toxicity as well. Despite its wide use in commercial products, the ecotoxicity of these micelles and the influence of the EO units on their toxicity still did not receive the necessary attention. In this context, the present study aimed at assessing the influence of the number of ethylene oxide (EO) units in the head groups of SLEnS on the toxicity of the SLEnS-LAS mixed micelles to the bacterium Vibrio fischeri (Microtox® assay, here used as a fast and preliminary ecotoxicological indicator). The SLEnS variants with fewer EO units showed higher toxicity relatively to those with more EO units - EC50 range (0-50 EO units): 0.56-8.59 mg L-1, thus they can be suggested as environmentally safer variants to be used in personal care and household products. Provided the consistency of Microtox® results as obtained here, this quick and cost-effective procedure can be an important tool towards the development of eco-friendlier surfactant-based formulations.
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Affiliation(s)
- Nuno Martins
- Department of Biology & CESAM, University of Aveiro, Aveiro, Portugal
| | - Joana L Pereira
- Department of Biology & CESAM, University of Aveiro, Aveiro, Portugal
| | - Filipe E Antunes
- Department of Chemistry, University of Coimbra, Coimbra, Portugal
| | - Elodie Melro
- Department of Chemistry, University of Coimbra, Coimbra, Portugal
| | | | - Lídia Dias
- Department of Biology & CESAM, University of Aveiro, Aveiro, Portugal
| | | | - Isabel Lopes
- Department of Biology & CESAM, University of Aveiro, Aveiro, Portugal.
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12
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Exopolysaccharides from Marine and Marine Extremophilic Bacteria: Structures, Properties, Ecological Roles and Applications. Mar Drugs 2018; 16:md16020069. [PMID: 29461505 PMCID: PMC5852497 DOI: 10.3390/md16020069] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 02/08/2018] [Accepted: 02/16/2018] [Indexed: 11/16/2022] Open
Abstract
The marine environment is the largest aquatic ecosystem on Earth and it harbours microorganisms responsible for more than 50% of total biomass of prokaryotes in the world. All these microorganisms produce extracellular polymers that constitute a substantial part of the dissolved organic carbon, often in the form of exopolysaccharides (EPS). In addition, the production of these polymers is often correlated to the establishment of the biofilm growth mode, during which they are important matrix components. Their functions include adhesion and colonization of surfaces, protection of the bacterial cells and support for biochemical interactions between the bacteria and the surrounding environment. The aim of this review is to present a summary of the status of the research about the structures of exopolysaccharides from marine bacteria, including capsular, medium released and biofilm embedded polysaccharides. Moreover, ecological roles of these polymers, especially for those isolated from extreme ecological niches (deep-sea hydrothermal vents, polar regions, hypersaline ponds, etc.), are reported. Finally, relationships between the structure and the function of the exopolysaccharides are discussed.
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13
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Sándor V, Kilár A, Kilár F, Kocsis B, Dörnyei Á. Characterization of complex, heterogeneous lipid A samples using HPLC-MS/MS technique III. Positive-ion mode tandem mass spectrometry to reveal phosphorylation and acylation patterns of lipid A. JOURNAL OF MASS SPECTROMETRY : JMS 2018; 53:146-161. [PMID: 29144587 DOI: 10.1002/jms.4046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 10/29/2017] [Accepted: 10/30/2017] [Indexed: 06/07/2023]
Abstract
In this study, we report the detailed analysis of the fragmentation patterns of positively charged lipid A species based on their tandem mass spectra obtained under low-energy collision-induced dissociation conditions of an electrospray quadrupole time-of-flight mass spectrometer. The tandem mass spectrometry experiments were performed after the separation of the compounds with a reversed-phase high performance liquid chromatography method. We found that both, phosphorylated and nonphosphorylated lipid A molecules can be readily ionized in the positive-ion mode by adduct formation with triethylamine added to the eluent. The tandem mass spectra of the lipid A triethylammonium adduct ions showed several product ions corresponding to inter-ring glycosidic cleavages of the sugar residues, as well as consecutive and competitive eliminations of fatty acids, phosphoric acid, and water following the neutral loss of triethylamine. Characteristic product ions provided direct information on the phosphorylation site(s), also when phosphorylation isomers (ie, containing either a C1 or a C4' phosphate group) were simultaneously present in the sample. Continuous series of high-abundance B-type and low-abundance Y-type inter-ring fragment ions were indicative of the fatty acyl distribution between the nonreducing and reducing ends of the lipid A backbone. The previously reported lipid A structures of Proteus morganii O34 and Escherichia coli O111 bacteria were used as standards. Although, the fragmentation pathways of the differently phosphorylated lipid A species significantly differed in the negative-ion mode, they were very similar in the positive-ion mode. The complementary use of positive-ion and negative-ion mode tandem mass spectrometry was found to be essential for the full structural characterization of the C1-monophosphorylated lipid A species.
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Affiliation(s)
- Viktor Sándor
- Institute of Bioanalysis, Medical School and Szentágothai Research Centre, University of Pécs, Szigeti út 12, 7624, Pécs, Hungary
| | - Anikó Kilár
- Institute of Bioanalysis, Medical School and Szentágothai Research Centre, University of Pécs, Szigeti út 12, 7624, Pécs, Hungary
- Department of Analytical and Environmental Chemistry, Faculty of Sciences, University of Pécs, Ifjúság útja 6, 7624, Pécs, Hungary
| | - Ferenc Kilár
- Institute of Bioanalysis, Medical School and Szentágothai Research Centre, University of Pécs, Szigeti út 12, 7624, Pécs, Hungary
- Department of Analytical and Environmental Chemistry, Faculty of Sciences, University of Pécs, Ifjúság útja 6, 7624, Pécs, Hungary
| | - Béla Kocsis
- Department of Medical Microbiology and Immunology, Medical School, University of Pécs, Szigeti út 12, 7624, Pécs, Hungary
| | - Ágnes Dörnyei
- Department of Analytical and Environmental Chemistry, Faculty of Sciences, University of Pécs, Ifjúság útja 6, 7624, Pécs, Hungary
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14
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Ziaco M, Górska S, Traboni S, Razim A, Casillo A, Iadonisi A, Gamian A, Corsaro MM, Bedini E. Development of Clickable Monophosphoryl Lipid A Derivatives toward Semisynthetic Conjugates with Tumor-Associated Carbohydrate Antigens. J Med Chem 2017; 60:9757-9768. [DOI: 10.1021/acs.jmedchem.7b01234] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Marcello Ziaco
- Department
of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo, via Cintia 4, I-80126 Napoli, Italy
| | - Sabina Górska
- L. Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Weigla 12, 53-114 Wrocław, Poland
| | - Serena Traboni
- Department
of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo, via Cintia 4, I-80126 Napoli, Italy
| | - Agnieszka Razim
- L. Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Weigla 12, 53-114 Wrocław, Poland
| | - Angela Casillo
- Department
of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo, via Cintia 4, I-80126 Napoli, Italy
| | - Alfonso Iadonisi
- Department
of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo, via Cintia 4, I-80126 Napoli, Italy
| | - Andrzej Gamian
- L. Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Weigla 12, 53-114 Wrocław, Poland
| | - Maria Michela Corsaro
- Department
of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo, via Cintia 4, I-80126 Napoli, Italy
| | - Emiliano Bedini
- Department
of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo, via Cintia 4, I-80126 Napoli, Italy
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15
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Casillo A, Ziaco M, Lindner B, Parrilli E, Schwudke D, Holgado A, Verstrepen L, Sannino F, Beyaert R, Lanzetta R, Tutino ML, Corsaro MM. Unusual Lipid A from a Cold-Adapted Bacterium: Detailed Structural Characterization. Chembiochem 2017. [PMID: 28650563 DOI: 10.1002/cbic.201700287] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Colwellia psychrerythraea 34H is a Gram-negative cold-adapted microorganism that adopts many strategies to cope with the limitations associated with the low temperatures of its habitat. In this study, we report the complete characterization of the lipid A moiety from the lipopolysaccharide of Colwellia. Lipid A and its partially deacylated derivative were completely characterized by high-resolution mass spectrometry, NMR spectroscopy, and chemical analysis. An unusual structure with a 3-hydroxy unsaturated tetradecenoic acid as a component of the primary acylation pattern was identified. In addition, the presence of a partially acylated phosphoglycerol moiety on the secondary acylation site at the 3-position of the reducing 2-amino-2-deoxyglucopyranose unit caused tremendous natural heterogeneity in the structure of lipid A. Biological-activity assays indicated that C. psychrerythraea 34H lipid A did not show an agonistic or antagonistic effect upon testing in human macrophages.
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Affiliation(s)
- Angela Casillo
- Department of Chemical Sciences, University of Naples "Federico II", Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Naples, Italy
| | - Marcello Ziaco
- Department of Chemical Sciences, University of Naples "Federico II", Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Naples, Italy
| | - Buko Lindner
- Division of Bioanalytical Chemistry, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 10, 23845, Borstel, Germany
| | - Ermenegilda Parrilli
- Department of Chemical Sciences, University of Naples "Federico II", Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Naples, Italy
| | - Dominik Schwudke
- Division of Bioanalytical Chemistry, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 10, 23845, Borstel, Germany
| | - Aurora Holgado
- Unit for Molecular Signal Transduction in Inflammation, VIB-UGent Center for Inflammation Research, VIB, Technologiepark 927, 9052, Zwijnaarde, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Technologiepark 927, 9052, Zwijnaarde, Ghent, Belgium
| | - Lynn Verstrepen
- Unit for Molecular Signal Transduction in Inflammation, VIB-UGent Center for Inflammation Research, VIB, Technologiepark 927, 9052, Zwijnaarde, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Technologiepark 927, 9052, Zwijnaarde, Ghent, Belgium
| | - Filomena Sannino
- Department of Chemical Sciences, University of Naples "Federico II", Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Naples, Italy
| | - Rudi Beyaert
- Unit for Molecular Signal Transduction in Inflammation, VIB-UGent Center for Inflammation Research, VIB, Technologiepark 927, 9052, Zwijnaarde, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Technologiepark 927, 9052, Zwijnaarde, Ghent, Belgium
| | - Rosa Lanzetta
- Department of Chemical Sciences, University of Naples "Federico II", Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Naples, Italy
| | - Maria Luisa Tutino
- Department of Chemical Sciences, University of Naples "Federico II", Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Naples, Italy
| | - Maria Michela Corsaro
- Department of Chemical Sciences, University of Naples "Federico II", Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Naples, Italy
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16
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Harvey DJ. Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2011-2012. MASS SPECTROMETRY REVIEWS 2017; 36:255-422. [PMID: 26270629 DOI: 10.1002/mas.21471] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 01/15/2015] [Indexed: 06/04/2023]
Abstract
This review is the seventh update of the original article published in 1999 on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2012. General aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, and fragmentation are covered in the first part of the review and applications to various structural types constitute the remainder. The main groups of compound are oligo- and poly-saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Much of this material is presented in tabular form. Also discussed are medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. © 2015 Wiley Periodicals, Inc. Mass Spec Rev 36:255-422, 2017.
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Affiliation(s)
- David J Harvey
- Department of Biochemistry, Oxford Glycobiology Institute, University of Oxford, Oxford, OX1 3QU, UK
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17
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Lipid A structural modifications in extreme conditions and identification of unique modifying enzymes to define the Toll-like receptor 4 structure-activity relationship. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:1439-1450. [PMID: 28108356 DOI: 10.1016/j.bbalip.2017.01.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/10/2017] [Accepted: 01/12/2017] [Indexed: 01/23/2023]
Abstract
Strategies utilizing Toll-like receptor 4 (TLR4) agonists for treatment of cancer, infectious diseases, and other targets report promising results. Potent TLR4 antagonists are also gaining attention as therapeutic leads. Though some principles for TLR4 modulation by lipid A have been described, a thorough understanding of the structure-activity relationship (SAR) is lacking. Only through a complete definition of lipid A-TLR4 SAR is it possible to predict TLR4 signaling effects of discrete lipid A structures, rendering them more pharmacologically relevant. A limited 'toolbox' of lipid A-modifying enzymes has been defined and is largely composed of enzymes from mesophile human and zoonotic pathogens. Expansion of this 'toolbox' will result from extending the search into lipid A biosynthesis and modification by bacteria living at the extremes. Here, we review the fundamentals of lipid A structure, advances in lipid A uses in TLR4 modulation, and the search for novel lipid A-modifying systems in extremophile bacteria. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop.
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18
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Sándor V, Kilár A, Kilár F, Kocsis B, Dörnyei Á. Characterization of complex, heterogeneous lipid A samples using HPLC-MS/MS technique II. Structural elucidation of non-phosphorylated lipid A by negative-ion mode tandem mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2016; 51:615-628. [PMID: 28239963 DOI: 10.1002/jms.3786] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 05/09/2016] [Accepted: 05/11/2016] [Indexed: 06/06/2023]
Abstract
Non-phosphorylated lipid A species confer reduced inflammatory potential for the bacteria. Knowledge on their chemical structure and presence in bacterial pathogens may contribute to the understanding of bacterial resistance and activation of the host innate immune system. In this study, we report the fragmentation pathways of negatively charged, non-phosphorylated lipid A species under low-energy collision-induced dissociation conditions of an electrospray ionization quadrupole time-of-flight instrument. Charge-promoted consecutive and competitive eliminations of the acyl chains and cross-ring cleavages of the sugar residues were observed. The A-type fragment ion series and the complementary X-type fragment(s) with corresponding deprotonated carboxamide(s) were diagnostic for the distribution of the primary and secondary acyl residues on the non-reducing and the reducing ends, respectively, of the non-phosphorylated lipid A backbone. Reversed-phase liquid chromatography in combination with negative-ion electrospray ionization quadrupole time-of-flight tandem mass spectrometry could provide sufficient information on the primary and secondary acyl residues of a non-phosphorylated lipid A. As a standard, the hexa-acylated ion at m/z 1636 with the Escherichia coli-type acyl distribution (from E. coli O111) was used. The method was tested and refined with the analysis of other non-phosphorylated hexa- and several hepta-, penta-, and tetra-acylated lipid A species detected in crude lipid A fractions from E. coli O111 and Proteus morganii O34 bacteria. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Viktor Sándor
- Institute of Bioanalysis and Szentágothai Research Centre, University of Pécs, Szigeti út 12., 7624, Pécs, Hungary
| | - Anikó Kilár
- MTA-PTE Molecular Interactions in Separation Science Research Group, Ifjúság útja 6., 7624, Pécs, Hungary
| | - Ferenc Kilár
- Institute of Bioanalysis and Szentágothai Research Centre, University of Pécs, Szigeti út 12., 7624, Pécs, Hungary
- Department of Analytical and Environmental Chemistry, Faculty of Sciences, University of Pécs, Ifjúság útja 6., 7624, Pécs, Hungary
| | - Béla Kocsis
- Department of Medical Microbiology and Immunology, Faculty of Medicine, University of Pécs, Szigeti út 12., 7624, Pécs, Hungary
| | - Ágnes Dörnyei
- Department of Analytical and Environmental Chemistry, Faculty of Sciences, University of Pécs, Ifjúság útja 6., 7624, Pécs, Hungary
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19
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Phillips NJ, John CM, Jarvis GA. Analysis of Bacterial Lipooligosaccharides by MALDI-TOF MS with Traveling Wave Ion Mobility. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:1263-1276. [PMID: 27056565 DOI: 10.1007/s13361-016-1383-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 03/11/2016] [Accepted: 03/12/2016] [Indexed: 06/05/2023]
Abstract
Lipooligosaccharides (LOS) are major microbial virulence factors displayed on the outer membrane of rough-type Gram-negative bacteria. These amphipathic glycolipids are comprised of two domains, a core oligosaccharide linked to a lipid A moiety. Isolated LOS samples are generally heterogeneous mixtures of glycoforms, with structural variability in both domains. Traditionally, the oligosaccharide and lipid A components of LOS have been analyzed separately following mild acid hydrolysis, although important acid-labile moieties can be cleaved. Recently, an improved method was introduced for analysis of intact LOS by MALDI-TOF MS using a thin layer matrix composed of 2,4,6-trihydroxyacetophenone (THAP) and nitrocellulose. In addition to molecular ions, the spectra show in-source "prompt" fragments arising from regiospecific cleavage between the lipid A and oligosaccharide domains. Here, we demonstrate the use of traveling wave ion mobility spectrometry (TWIMS) for IMS-MS and IMS-MS/MS analyses of intact LOS from Neisseria spp. ionized by MALDI. Using IMS, the singly charged prompt fragments for the oligosaccharide and lipid A domains of LOS were readily separated into resolved ion plumes, permitting the extraction of specific subspectra, which led to increased confidence in assigning compositions and improved detection of less abundant ions. Moreover, IMS separation of precursor ions prior to collision-induced dissociation (CID) generated time-aligned, clean MS/MS spectra devoid of fragments from interfering species. Incorporating IMS into the profiling of intact LOS by MALDI-TOF MS exploits the unique domain structure of the molecule and offers a new means of extracting more detailed information from the analysis. Graphical Abstract ᅟ.
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Affiliation(s)
- Nancy J Phillips
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA, 94143, USA
| | - Constance M John
- Center for Immunochemistry, Veterans Affairs Medical Center, 4150 Clement Street, San Francisco, CA, 94121, USA
- Department of Laboratory Medicine, University of California, San Francisco, CA, 94143, USA
| | - Gary A Jarvis
- Center for Immunochemistry, Veterans Affairs Medical Center, 4150 Clement Street, San Francisco, CA, 94121, USA.
- Department of Laboratory Medicine, University of California, San Francisco, CA, 94143, USA.
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20
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Henderson JC, Zimmerman SM, Crofts AA, Boll JM, Kuhns LG, Herrera CM, Trent MS. The Power of Asymmetry: Architecture and Assembly of the Gram-Negative Outer Membrane Lipid Bilayer. Annu Rev Microbiol 2016; 70:255-78. [PMID: 27359214 DOI: 10.1146/annurev-micro-102215-095308] [Citation(s) in RCA: 141] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Determining the chemical composition of biological materials is paramount to the study of natural phenomena. Here, we describe the composition of model gram-negative outer membranes, focusing on the predominant assembly, an asymmetrical bilayer of lipid molecules. We also give an overview of lipid biosynthetic pathways and molecular mechanisms that organize this material into the outer membrane bilayer. An emphasis is placed on the potential of these pathways as targets for antibiotic development. We discuss deviations in composition, through bacterial cell surface remodeling, and alternative modalities to the asymmetric lipid bilayer. Outer membrane lipid alterations of current microbiological interest, such as lipid structures found in commensal bacteria, are emphasized. Additionally, outer membrane components could potentially be engineered to develop vaccine platforms. Observations related to composition and assembly of gram-negative outer membranes will continue to generate novel discoveries, broaden biotechnologies, and reveal profound mysteries to compel future research.
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Affiliation(s)
- Jeremy C Henderson
- Department of Molecular Biosciences, The University of Texas at Austin, Texas 78712
| | - Shawn M Zimmerman
- Department of Infectious Diseases, The University of Georgia, Athens, Georgia 30602;
| | - Alexander A Crofts
- Department of Molecular Biosciences, The University of Texas at Austin, Texas 78712
| | - Joseph M Boll
- Department of Molecular Biosciences, The University of Texas at Austin, Texas 78712
| | - Lisa G Kuhns
- Department of Infectious Diseases, The University of Georgia, Athens, Georgia 30602;
| | - Carmen M Herrera
- Department of Infectious Diseases, The University of Georgia, Athens, Georgia 30602;
| | - M Stephen Trent
- Department of Infectious Diseases, The University of Georgia, Athens, Georgia 30602;
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21
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Eshghi A, Henderson J, Trent MS, Picardeau M. Leptospira interrogans lpxD Homologue Is Required for Thermal Acclimatization and Virulence. Infect Immun 2015; 83:4314-21. [PMID: 26283339 PMCID: PMC4598399 DOI: 10.1128/iai.00897-15] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 08/13/2015] [Indexed: 12/20/2022] Open
Abstract
Leptospirosis is an emerging disease with an annual occurrence of over 1 million human cases worldwide. Pathogenic Leptospira bacteria are maintained in zoonotic cycles involving a diverse array of mammals, with the capacity to survive outside the host in aquatic environments. Survival in the diverse environments encountered by Leptospira likely requires various adaptive mechanisms. Little is known about Leptospira outer membrane modification systems, which may contribute to the capacity of these bacteria to successfully inhabit and colonize diverse environments and animal hosts. Leptospira bacteria carry two genes annotated as UDP-3-O-[3-hydroxymyristoyl] glucosamine N-acyltransferase genes (la0512 and la4326 [lpxD1 and lpxD2]) that in other bacteria are involved in the early steps of biosynthesis of lipid A, the membrane lipid anchor of lipopolysaccharide. Inactivation of only one of these genes, la0512/lpxD1, imparted sensitivity to the host physiological temperature (37°C) and rendered the bacteria avirulent in an animal infection model. Polymyxin B sensitivity assays revealed compromised outer membrane integrity in the lpxD1 mutant at host physiological temperature, but structural analysis of lipid A in the mutant revealed only minor changes in the lipid A moiety compared to that found in the wild-type strain. In accordance with this, an in trans complementation restored the phenotypes to a level comparable to that of the wild-type strain. These results suggest that the gene annotated as lpxD1 in Leptospira interrogans plays an important role in temperature adaptation and virulence in the animal infection model.
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Affiliation(s)
- Azad Eshghi
- Institut Pasteur, Biology of Spirochetes Unit, Paris, France
| | - Jeremy Henderson
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, USA
| | - M Stephen Trent
- Department of Infectious Disease, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
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22
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Structural and functional features of a developmentally regulated lipopolysaccharide-binding protein. mBio 2015; 6:e01193-15. [PMID: 26463160 PMCID: PMC4620459 DOI: 10.1128/mbio.01193-15] [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] [Indexed: 12/13/2022] Open
Abstract
Mammalian lipopolysaccharide (LPS) binding proteins (LBPs) occur mainly in extracellular fluids and promote LPS delivery to specific host cell receptors. The function of LBPs has been studied principally in the context of host defense; the possible role of LBPs in nonpathogenic host-microbe interactions has not been well characterized. Using the Euprymna scolopes-Vibrio fischeri model, we analyzed the structure and function of an LBP family protein, E. scolopes LBP1 (EsLBP1), and provide evidence for its role in triggering a symbiont-induced host developmental program. Previous studies showed that, during initial host colonization, the LPS of V. fischeri synergizes with peptidoglycan (PGN) monomer to induce morphogenesis of epithelial tissues of the host animal. Computationally modeled EsLBP1 shares some but not all structural features of mammalian LBPs that are thought important for LPS binding. Similar to human LBP, recombinant EsLBP1 expressed in insect cells bound V. fischeri LPS and Neisseria meningitidis lipooligosaccharide (LOS) with nanomolar or greater affinity but bound Francisella tularensis LPS only weakly and did not bind PGN monomer. Unlike human LBP, EsLBP1 did not bind N. meningitidis LOS:CD14 complexes. The eslbp1 transcript was upregulated ~22-fold by V. fischeri at 24 h postinoculation. Surprisingly, this upregulation was not induced by exposure to LPS but, rather, to the PGN monomer alone. Hybridization chain reaction-fluorescent in situ hybridization (HCR-FISH) and immunocytochemistry (ICC) localized eslbp1 transcript and protein in crypt epithelia, where V. fischeri induces morphogenesis. The data presented here provide a window into the evolution of LBPs and the scope of their roles in animal symbioses. Mammalian lipopolysaccharide (LPS)-binding protein (LBP) is implicated in conveying LPS to host cells and potentiating its signaling activity. In certain disease states, such as obesity, the overproduction of this protein has been a reliable biomarker of chronic inflammation. Here, we describe a symbiosis-induced invertebrate LBP whose tertiary structure and LPS-binding characteristics are similar to those of mammalian LBPs; however, the primary structure of this distantly related squid protein (EsLBP1) differs in key residues previously believed to be essential for LPS binding, suggesting that an alternative strategy exists. Surprisingly, symbiotic expression of eslbp1 is induced by peptidoglycan derivatives, not LPS, a pattern converse to that of RegIIIγ, an important mammalian immunity protein that binds peptidoglycan but whose gene expression is induced by LPS. Finally, EsLBP1 occurs along the apical surfaces of all the host’s epithelia, suggesting that it was recruited from a general defensive role to one that mediates specific interactions with its symbiont.
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23
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Lipopolysaccharides from Commensal and Opportunistic Bacteria: Characterization and Response of the Immune System of the Host Sponge Suberites domuncula. Mar Drugs 2015; 13:4985-5006. [PMID: 26262625 PMCID: PMC4557011 DOI: 10.3390/md13084985] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 07/17/2015] [Accepted: 07/20/2015] [Indexed: 12/29/2022] Open
Abstract
Marine sponges harbor a rich bacterioflora with which they maintain close relationships. However, the way these animals make the distinction between bacteria which are consumed to meet their metabolic needs and opportunistic and commensal bacteria which are hosted is not elucidated. Among the elements participating in this discrimination, bacterial cell wall components such as lipopolysaccharides (LPS) could play a role. In the present study, we investigated the LPS chemical structure of two bacteria associated with the sponge Suberites domuncula: a commensal Endozoicomonas sp. and an opportunistic Pseudoalteromonas sp. Electrophoretic patterns indicated different LPS structures for these bacteria. The immunomodulatory lipid A was isolated after mild acetic acid hydrolysis. The electrospray ionization ion-trap mass spectra revealed monophosphorylated molecules corresponding to tetra- and pentaacylated structures with common structural features between the two strains. Despite peculiar structural characteristics, none of these two LPS influenced the expression of the macrophage-expressed gene S. domuncula unlike the Escherichia coli ones. Further research will have to include a larger number of genes to understand how this animal can distinguish between LPS with resembling structures and discriminate between bacteria associated with it.
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Sweet CR, Watson RE, Landis CA, Smith JP. Temperature-Dependence of Lipid A Acyl Structure in Psychrobacter cryohalolentis and Arctic Isolates of Colwellia hornerae and Colwellia piezophila. Mar Drugs 2015; 13:4701-20. [PMID: 26264000 PMCID: PMC4557000 DOI: 10.3390/md13084701] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 07/19/2015] [Accepted: 07/20/2015] [Indexed: 12/21/2022] Open
Abstract
Lipid A is a fundamental Gram-negative outer membrane component and the essential element of lipopolysaccharide (endotoxin), a potent immunostimulatory molecule. This work describes the metabolic adaptation of the lipid A acyl structure by Psychrobacter cryohalolentis at various temperatures in its facultative psychrophilic growth range, as characterized by MALDI-TOF MS and FAME GC-MS. It also presents the first elucidation of lipid A structure from the Colwellia genus, describing lipid A from strains of Colwellia hornerae and Colwellia piezophila, which were isolated as primary cultures from Arctic fast sea ice and identified by 16S rDNA sequencing. The Colwellia strains are obligate psychrophiles, with a growth range restricted to 15 °C or less. As such, these organisms have less need for fluidity adaptation in the acyl moiety of the outer membrane, and they do not display alterations in lipid A based on growth temperature. Both Psychrobacter and Colwellia make use of extensive single-methylene variation in the size of their lipid A molecules. Such single-carbon variations in acyl size were thought to be restricted to psychrotolerant (facultative) species, but its presence in these Colwellia species shows that odd-chain acyl units and a single-carbon variation in lipid A structure are present in obligate psychrophiles, as well.
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Affiliation(s)
- Charles R Sweet
- Chemistry Department, 572M Holloway Road, United States Naval Academy, Annapolis, MD 21402, USA.
| | - Rebecca E Watson
- Chemistry Department, 572M Holloway Road, United States Naval Academy, Annapolis, MD 21402, USA.
| | - Corinne A Landis
- Chemistry Department, 572M Holloway Road, United States Naval Academy, Annapolis, MD 21402, USA.
| | - Joseph P Smith
- Oceanography Department, 572C Holloway Road, United States Naval Academy, Annapolis, MD 21402, USA.
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Destoumieux-Garzón D, Duperthuy M, Vanhove AS, Schmitt P, Wai SN. Resistance to Antimicrobial Peptides in Vibrios. Antibiotics (Basel) 2014; 3:540-63. [PMID: 27025756 PMCID: PMC4790380 DOI: 10.3390/antibiotics3040540] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 09/25/2014] [Accepted: 10/08/2014] [Indexed: 12/19/2022] Open
Abstract
Vibrios are associated with a broad diversity of hosts that produce antimicrobial peptides (AMPs) as part of their defense against microbial infections. In particular, vibrios colonize epithelia, which function as protective barriers and express AMPs as a first line of chemical defense against pathogens. Recent studies have shown they can also colonize phagocytes, key components of the animal immune system. Phagocytes infiltrate infected tissues and use AMPs to kill the phagocytosed microorganisms intracellularly, or deliver their antimicrobial content extracellularly to circumvent tissue infection. We review here the mechanisms by which vibrios have evolved the capacity to evade or resist the potent antimicrobial defenses of the immune cells or tissues they colonize. Among their strategies to resist killing by AMPs, primarily vibrios use membrane remodeling mechanisms. In particular, some highly resistant strains substitute hexaacylated Lipid A with a diglycine residue to reduce their negative surface charge, thereby lowering their electrostatic interactions with cationic AMPs. As a response to envelope stress, which can be induced by membrane-active agents including AMPs, vibrios also release outer membrane vesicles to create a protective membranous shield that traps extracellular AMPs and prevents interaction of the peptides with their own membranes. Finally, once AMPs have breached the bacterial membrane barriers, vibrios use RND efflux pumps, similar to those of other species, to transport AMPs out of their cytoplasmic space.
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Affiliation(s)
- Delphine Destoumieux-Garzón
- Ecology of Coastal Marine Systems, CNRS, Ifremer, University of Montpellier, IRD, Place Eugène Bataillon, CC80, 34095 Montpellier, France.
| | - Marylise Duperthuy
- Department of Molecular Biology, The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 901 87 Umeå, Sweden.
| | - Audrey Sophie Vanhove
- Ecology of Coastal Marine Systems, CNRS, Ifremer, University of Montpellier, IRD, Place Eugène Bataillon, CC80, 34095 Montpellier, France.
| | - Paulina Schmitt
- Laboratorio de Genética e Inmunología Molecular, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, 2373223 Valparaíso, Chile.
| | - Sun Nyunt Wai
- Department of Molecular Biology, The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 901 87 Umeå, Sweden.
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Brennan CA, Hunt JR, Kremer N, Krasity BC, Apicella MA, McFall-Ngai MJ, Ruby EG. A model symbiosis reveals a role for sheathed-flagellum rotation in the release of immunogenic lipopolysaccharide. eLife 2014; 3:e01579. [PMID: 24596150 PMCID: PMC3941163 DOI: 10.7554/elife.01579] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Bacterial flagella mediate host–microbe interactions through tissue tropism during colonization, as well as by activating immune responses. The flagellar shaft of some bacteria, including several human pathogens, is encased in a membranous sheath of unknown function. While it has been hypothesized that the sheath may allow these bacteria to evade host responses to the immunogenic flagellin subunit, this unusual structural feature has remained an enigma. Here we demonstrate that the rotation of the sheathed flagellum in both the mutualist Vibrio fischeri and the pathogen Vibrio cholerae promotes release of a potent bacteria-derived immunogen, lipopolysaccharide, found in the flagellar sheath. We further present a new role for the flagellar sheath in triggering, rather than circumventing, host immune responses in the model squid-vibrio symbiosis. Such an observation not only has implications for the study of bacterial pathogens with sheathed flagella, but also raises important biophysical questions of sheathed-flagellum function. DOI:http://dx.doi.org/10.7554/eLife.01579.001 While a few of the bacteria that live in and on the bodies of humans and other animals are harmful and can cause disease, most others can offer benefits to their hosts. Many bacteria—including some important human pathogens—have tails called flagella that rotate to move the bacteria inside its host. However, the immune system can detect parts of these flagella and eliminate the pathogen. Bacterial flagella are made from filaments of proteins, and some flagella are also enclosed by a sheath that is similar to the outer membrane that encloses certain bacteria. The function of this sheath is unclear, although some researchers have suggested that it might prevent the immune system from detecting the proteins in the flagellum. Now, by studying the interactions between the Hawaiian bobtail squid and a marine bacterium, Brennan et al. show that the sheath can actually alert the host that the bacteria are around. The Hawaiian bobtail squid collects bioluminescent bacteria within a so-called ‘light organ’. This organ undergoes a number of developmental changes to house the bacteria, and the squid then uses the light from the bacteria to mask its own shadow, which helps it to avoid being detected by predators. Brennan et al. compared how wild-type bacteria and mutant bacteria that either had no flagella, or had flagella that did not rotate, interacted with young squid. Only bacteria with working flagella were able to trigger the normal development of the squid’s light organ, which suggests that the rotating flagella are releasing the signal that tells the squid that the beneficial bacteria are present. Brennan et al. demonstrated that the rotation of sheathed flagella led to the release of a molecule called lipopolysaccharide. This molecule is known to activate the immune system in animals, and it is one of the bacterial signals that the squid responds to. Moreover, when the flagella of other bacteria with sheaths—such as those that cause cholera—are rotating, there is also an increase in the release of lipopolysaccharide. However, rotation of the flagella of bacteria without sheaths has no such effect. The next challenge will be to test the importance of this release of lipopolysaccharide from rotating flagella on the outcome of bacterial diseases of humans and other animals. DOI:http://dx.doi.org/10.7554/eLife.01579.002
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Affiliation(s)
- Caitlin A Brennan
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, United States
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Casabuono AC, van der Ploeg CA, Rogé AD, Bruno SB, Couto AS. Characterization of lipid A profiles from Shigella flexneri variant X lipopolysaccharide. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2012; 26:2011-2020. [PMID: 22847700 DOI: 10.1002/rcm.6306] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
RATIONALE In developing countries, Shigella flexneri (Sf) is the major causative agent of the endemic shigellosis (bacillary dysentery) responsible annually for one million fatalities mostly among infants. Lipopolysaccharides (LPSs) are characteristic components of the outer membrane of the overwhelming majority of Gram-negative bacteria. Since lipid A is essential for the viability of the Gram-negative bacteria, it is subject to extensive chemical studies with new analytical techniques. METHODS Lipid A was released by mild acid hydrolysis from the lipopolysaccharide which was obtained via the phenol/water extraction, purified and analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and matrix-assisted laser desorption/ionization laser-induced dissociation tandem mass spectrometry (MALDI-LID-MS/MS). RESULTS A detailed structural study of the whole lipid A obtained from S. flexneri variant X was carried out for the first time. Thus, we have shown that lipid A is a heterogeneous mixture having different numbers of acylated and phosphoethanolamine groups attached to the diglucosamine backbone. Furthermore, we found in the phenol phase an unusual hepta-acylated lipid A species, although the abundance was very low. CONCLUSIONS MALDI-TOF-MS allowed us to unravel the lipid A heterogeneity, which was not previously reported in Sf LPS. It is well known that slight variations of the chemical structure of lipid A may change its biological activity. Thus, the knowledge of the detailed chemical structure represents an essential step for further development of new preventive or therapeutically active compounds.
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Affiliation(s)
- Adriana C Casabuono
- CIHIDECAR, Departamento de Química Orgánica, Facultad de Cs Exactas y Naturales, Universidad de Buenos Aires, Pabellón II, Cdad. Universitaria, Bs. As., Argentina
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Modulation of symbiont lipid A signaling by host alkaline phosphatases in the squid-vibrio symbiosis. mBio 2012; 3:mBio.00093-12. [PMID: 22550038 PMCID: PMC3569863 DOI: 10.1128/mbio.00093-12] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
UNLABELLED The synergistic activity of Vibrio fischeri lipid A and the peptidoglycan monomer (tracheal cytotoxin [TCT]) induces apoptosis in the superficial cells of the juvenile Euprymna scolopes light organ during the onset of the squid-vibrio symbiosis. Once the association is established in the epithelium-lined crypts of the light organ, the host degrades the symbiont's constitutively produced TCT by the amidase activity of a peptidoglycan recognition protein (E. scolopes peptidoglycan recognition protein 2 [EsPGRP2]). In the present study, we explored the role of alkaline phosphatases in transforming the lipid A of the symbiont into a form that changes its signaling properties to host tissues. We obtained full-length open reading frames for two E. scolopes alkaline phosphatase (EsAP) mRNAs (esap1 and esap2); transcript levels suggested that the dominant light organ isoform is EsAP1. Levels of total EsAP activity increased with symbiosis, but only after the lipid A-dependent morphogenetic induction at 12 h, and were regulated over the day-night cycle. Inhibition of total EsAP activity impaired normal colonization and persistence by the symbiont. EsAP activity localized to the internal regions of the symbiotic juvenile light organ, including the lumina of the crypt spaces where the symbiont resides. These data provide evidence that EsAPs work in concert with EsPGRPs to change the signaling properties of bacterial products and thereby promote persistent colonization by the mutualistic symbiont. IMPORTANCE The potential for microbe-associated molecular patterns (MAMPs) to compromise host-tissue health is reflected in the often-used nomenclature for these molecules: lipopolysaccharide (LPS) is also called "endotoxin" and the peptidoglycan monomer is also called "tracheal cytotoxin" (TCT). With constant presentation of MAMPs by the normal microbiota, mechanisms to tolerate their effects have developed. The results of this contribution provide evidence that host alkaline phosphatases (APs) dephosphorylate and inactivate the symbiont MAMP lipid A. As such, APs work in synergy with a peptidoglycan recognition protein, which inactivates symbiont-exported TCT, to alter the symbiont MAMPs and promote persistence of the partnership. Not only may these activities serve to "tame" the MAMPs, but also the resulting products may themselves be important signals in persistent mutualisms. The finding of lipid A modification by APs in an invertebrate mutualism provides evidence that this specific strategy for dealing with symbiotic partners is conserved across the animal kingdom.
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Post DMB, Yu L, Krasity BC, Choudhury B, Mandel MJ, Brennan CA, Ruby EG, McFall-Ngai MJ, Gibson BW, Apicella MA. O-antigen and core carbohydrate of Vibrio fischeri lipopolysaccharide: composition and analysis of their role in Euprymna scolopes light organ colonization. J Biol Chem 2012; 287:8515-30. [PMID: 22247546 DOI: 10.1074/jbc.m111.324012] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Vibrio fischeri exists in a symbiotic relationship with the Hawaiian bobtail squid, Euprymna scolopes, where the squid provides a home for the bacteria, and the bacteria in turn provide camouflage that helps protect the squid from night-time predators. Like other gram-negative organisms, V. fischeri expresses lipopolysaccharide (LPS) on its cell surface. The structure of the O-antigen and the core components of the LPS and their possible role in colonization of the squid have not previously been determined. In these studies, an O-antigen ligase mutant, waaL, was utilized to determine the structures of these LPS components and their roles in colonization of the squid. WaaL ligates the O-antigen to the core of the LPS; thus, LPS from waaL mutants lacks O-antigen. Our results show that the V. fischeri waaL mutant has a motility defect, is significantly delayed in colonization, and is unable to compete with the wild-type strain in co-colonization assays. Comparative analyses of the LPS from the wild-type and waaL strains showed that the V. fischeri LPS has a single O-antigen repeat composed of yersiniose, 8-epi-legionaminic acid, and N-acetylfucosamine. In addition, the LPS from the waaL strain showed that the core structure consists of L-glycero-D-manno-heptose, D-glycero-D-manno-heptose, glucose, 3-deoxy-D-manno-octulosonic acid, N-acetylgalactosamine, 8-epi-legionaminic acid, phosphate, and phosphoethanolamine. These studies indicate that the unusual V. fischeri O-antigen sugars play a role in the early phases of bacterial colonization of the squid.
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Affiliation(s)
- Deborah M B Post
- Buck Institute for Research on Aging, Novato, California 94945, USA
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Hankins JV, Madsen JA, Giles DK, Childers BM, Klose KE, Brodbelt JS, Trent MS. Elucidation of a novel Vibrio cholerae lipid A secondary hydroxy-acyltransferase and its role in innate immune recognition. Mol Microbiol 2011; 81:1313-29. [PMID: 21752109 PMCID: PMC3178793 DOI: 10.1111/j.1365-2958.2011.07765.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Similar to most Gram-negative bacteria, the outer leaflet of the outer membrane of Vibrio cholerae is comprised of lipopolysaccharide. Previous reports have proposed that V. cholerae serogroups O1 and O139 synthesize structurally different lipid A domains, which anchor lipopolysaccharide within the outer membrane. In the current study, intact lipid A species of V. cholerae O1 and O139 were analysed by mass spectrometry. We demonstrate that V. cholerae serogroups associated with human disease synthesize a similar asymmetrical hexa-acylated lipid A species, bearing a myristate (C14:0) and 3-hydroxylaurate (3-OH C12:0) at the 2'- and 3'-positions respectively. A previous report from our laboratory characterized the V. cholerae LpxL homologue Vc0213, which transfers a C14:0 to the 2'-position of the glucosamine disaccharide. Our current findings identify V. cholerae Vc0212 as a novel lipid A secondary hydroxy-acyltransferase, termed LpxN, responsible for transferring the 3-hydroxylaurate (3-OH C12:0) to the V. cholerae lipid A domain. Importantly, the presence of a 3-hydroxyl group on the 3'-linked secondary acyl chain was found to promote antimicrobial peptide resistance in V. cholerae; however, this functional group was not required for activation of the innate immune response.
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Affiliation(s)
- Jessica V Hankins
- Department of Biochemistry and Molecular Biology, Georgia Health Sciences University, Augusta, GA 30912, USA
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