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Anderson T, Jiang H, Cheallaigh AN, Bengtsson D, Oscarson S, Cairns C, St Michael F, Cox A, Kuttel MM. Formation and immunological evaluation of Moraxella catarrhalis glycoconjugates based on synthetic oligosaccharides. Carbohydr Polym 2024; 332:121928. [PMID: 38431400 DOI: 10.1016/j.carbpol.2024.121928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/31/2024] [Accepted: 02/06/2024] [Indexed: 03/05/2024]
Abstract
Published work has shown that glycoconjugate vaccines, based on truncated detoxified lipopolysaccharides from Moraxella catarrhalis attached through their reducing end to a carrier protein, gave good protection for all three serotypes A, B, and C in mice immunisation experiments. The (from the non-reducing end) truncated LPS structures were obtained from bacterial glycosyl transferase knock-out mutants and contained the de-esterified Lipid A, two Kdo residues and five glucose moieties. This work describes the chemical synthesis of the same outer Moraxella LPS structures, spacer-equipped and further truncated from the reducing end, i.e., without the Lipid A part and containing four or five glucose moieties or four glucose moieties and one Kdo residue, and their subsequent conjugation to a carrier protein via a five‑carbon bifunctional spacer to form glycoconjugates. Immunisation experiments both in mice and rabbits of these gave a good antibody response, being 2-7 times that of pre-immune sera. However, the sera produced only recognized the immunizing glycan immunogens and failed to bind to native LPS or whole bacterial cells. Comparative molecular modelling of three alternative antigens shows that an additional (2 → 4)-linked Kdo residue, not present in the synthetic structures, has a significant impact on the shape and volume of the molecule, with implications for antigen binding and cross-reactivity.
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Affiliation(s)
- Taigh Anderson
- Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
| | - Hao Jiang
- Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
| | - Aisling Ní Cheallaigh
- Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
| | - Dennis Bengtsson
- Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
| | - Stefan Oscarson
- Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Chantelle Cairns
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Frank St Michael
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Andrew Cox
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Michelle M Kuttel
- Department of Computer Science, University of Cape Town, Cape Town 7701, South Africa
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Pither MD, Andretta E, Rocca G, Balzarini F, Matamoros-Recio A, Colicchio R, Salvatore P, van Kooyk Y, Silipo A, Granucci F, Martin-Santamaria S, Chiodo F, Molinaro A, Di Lorenzo F. Deciphering the Chemical Language of the Immunomodulatory Properties of Veillonella parvula Lipopolysaccharide. Angew Chem Int Ed Engl 2024; 63:e202401541. [PMID: 38393988 DOI: 10.1002/anie.202401541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 02/22/2024] [Accepted: 02/23/2024] [Indexed: 02/25/2024]
Abstract
Veillonella parvula, prototypical member of the oral and gut microbiota, is at times commensal yet also potentially pathogenic. The definition of the molecular basis tailoring this contrasting behavior is key for broadening our understanding of the microbiota-driven pathogenic and/or tolerogenic mechanisms that take place within our body. In this study, we focused on the chemistry of the main constituent of the outer membrane of V. parvula, the lipopolysaccharide (LPS). LPS molecules indeed elicit pro-inflammatory and immunomodulatory responses depending on their chemical structures. Herein we report the structural elucidation of the LPS from two strains of V. parvula and show important and unprecedented differences in both the lipid and carbohydrate moieties, including the identification of a novel galactofuranose and mannitol-containing O-antigen repeating unit for one of the two strains. Furthermore, by harnessing computational studies, in vitro human cell models, as well as lectin binding solid-phase assays, we discovered that the two chemically diverse LPS immunologically behave differently and have attempted to identify the molecular determinant(s) governing this phenomenon. Whereas pro-inflammatory potential has been evidenced for the lipid A moiety, by contrast a plausible "immune modulating" action has been proposed for the peculiar O-antigen portion.
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Affiliation(s)
- Molly Dorothy Pither
- Department of Chemical Sciences, University of Naples Federico II, via Cinthia, 4, 80126, Naples, Italy
| | - Emanuela Andretta
- Department of Chemical Sciences, University of Naples Federico II, via Cinthia, 4, 80126, Naples, Italy
| | - Giuseppe Rocca
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza dell'Ateneo Nuovo, 1, 20126, Milan, Italy
| | - Fabio Balzarini
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, Vrije Universiteit Amsterdam, 1007 MB, Amsterdam, The Netherlands
| | - Alejandra Matamoros-Recio
- Department of Structural and Chemical Biology, Centro de Investigaciones Biológicas, CIB-CSIC, C/ Ramiro de Maeztu, 9, 28040, Madrid, Spain
| | - Roberta Colicchio
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via Pansini, 5, 80131, Naples, Italy
| | - Paola Salvatore
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via Pansini, 5, 80131, Naples, Italy
| | - Yvette van Kooyk
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, Vrije Universiteit Amsterdam, 1007 MB, Amsterdam, The Netherlands
| | - Alba Silipo
- Department of Chemical Sciences, University of Naples Federico II, via Cinthia, 4, 80126, Naples, Italy
| | - Francesca Granucci
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza dell'Ateneo Nuovo, 1, 20126, Milan, Italy
| | - Sonsoles Martin-Santamaria
- Department of Structural and Chemical Biology, Centro de Investigaciones Biológicas, CIB-CSIC, C/ Ramiro de Maeztu, 9, 28040, Madrid, Spain
| | - Fabrizio Chiodo
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, Vrije Universiteit Amsterdam, 1007 MB, Amsterdam, The Netherlands
- Institute of Biomolecular Chemistry, National Research Council (CNR), Via Campi Flegrei, 34, 80078, Pozzuoli, Naples, Italy
| | - Antonio Molinaro
- Department of Chemical Sciences, University of Naples Federico II, via Cinthia, 4, 80126, Naples, Italy
| | - Flaviana Di Lorenzo
- Department of Chemical Sciences, University of Naples Federico II, via Cinthia, 4, 80126, Naples, Italy
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Mettlach JA, Cian MB, Chakraborty M, Dalebroux ZD. Signaling through the Salmonella PbgA-LapB regulatory complex activates LpxC proteolysis and limits lipopolysaccharide biogenesis during stationary-phase growth. J Bacteriol 2024; 206:e0030823. [PMID: 38534107 PMCID: PMC11025326 DOI: 10.1128/jb.00308-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 02/27/2024] [Indexed: 03/28/2024] Open
Abstract
Salmonella enterica serovar Typhimurium (S. Typhimurium) controls lipopolysaccharide (LPS) biosynthesis by regulating proteolysis of LpxC, the rate-limiting enzyme and target of preclinical antibiotics. PbgA/YejM/LapC regulates LpxC levels and controls outer membrane (OM) LPS composition at the log-to-stationary phase transition. Suppressor substitutions in LPS assembly protein B (LapB/YciM) rescue the LPS and OM integrity defects of pbgA-mutant S. Typhimurium. We hypothesized that PbgA regulates LpxC proteolysis by controlling LapB's ability to bind LpxC as a function of the growth phase. According to existing models, when nutrients are abundant, PbgA binds and restricts LapB from interacting with LpxC and FtsH, which limits LpxC proteolysis. However, when nutrients are limited, there is debate whether LapB dissociates from PbgA to bind LpxC and FtsH to enhance degradation. We sought to examine these models and investigate how the structure of LapB enables salmonellae to control LpxC proteolysis and LPS biosynthesis. Salmonellae increase LapB levels during the stationary phase to promote LpxC degradation, which limits lipid A-core production and increases their survival. The deletion of lapB, resulting in unregulated lipid A-core production and LpxC overabundance, leads to bacterial growth retardation. Tetratricopeptide repeats near the cytosol-inner membrane interface are sufficient for LapB to bind LpxC, and remarkably, LapB and PbgA interact in both growth phases, yet LpxC only associates with LapB in the stationary phase. Our findings support that PbgA-LapB exists as a constitutive complex in S. Typhimurium, which differentially binds LpxC to control LpxC proteolysis and limit lipid A-core biosynthesis in response to changes in the environment.IMPORTANCEAntimicrobial resistance has been a costly setback for human health and agriculture. Continued pursuit of new antibiotics and targets is imperative, and an improved understanding of existing ones is necessary. LpxC is an essential target of preclinical trial antibiotics that can eliminate multidrug-resistant Gram-negative bacterial infections. LapB is a natural LpxC inhibitor that targets LpxC for degradation and limits lipopolysaccharide production in Enterobacteriaceae. Contrary to some studies, findings herein support that LapB remains in complex instead of dissociating from its presumed negative regulator, PbgA/YejM/LapC, under conditions where LpxC proteolysis is enhanced. Advanced comprehension of this critical protein-lipid signaling network will lead to future development and refinement of small molecules that can specifically interfere.
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Affiliation(s)
- Joshua A. Mettlach
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Melina B. Cian
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Medha Chakraborty
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Zachary D. Dalebroux
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
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Su Z, Chen A, Lipkowski J. Electrochemical and Infrared Studies of a Model Bilayer of the Outer Membrane of Gram-Negative Bacteria and its Interaction with polymyxin─the Last-Resort Antibiotic. Langmuir 2024; 40:8248-8259. [PMID: 38578277 DOI: 10.1021/acs.langmuir.4c00480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
A model bilayer of the outer membrane (OM) of Gram-negative bacteria, composed of lipid A and 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE), was assembled on the β-Tg modified gold (111) single crystal surface using a combination of Langmuir-Blodgett and Langmuir-Schaefer transfer. Electrochemical and spectroscopic methods were employed to study the properties of the model bilayer and its interaction with polymyxin. The model bilayer is stable on the gold surface in the transmembrane potential region between 0.0 and -0.7 V. The presence of Mg2+ coordinates with the phosphate and carboxylate groups in the leaflet of lipid A and stabilizes the structure of the model bilayer. Polymyxin causes the model bilayer leakage and damage in the transmembrane potential region between 0.2 and -0.4 V. At transmembrane potentials lower than -0.5 V, polymyxin does not affect the membrane integrity. Polymyxin binds to the phosphate and carboxylate groups in lipid A molecules and causes the increase of the tilt angle of acyl chains and the decrease of the tilt of the C═O bond. The results in this paper indicate that the antimicrobial activity of polymyxin depends on the transmembrane potential at the model bilayer and provides useful information for the development of new antibiotics.
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Affiliation(s)
- ZhangFei Su
- Electrochemical Technology Center, Department of Chemistry, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Aicheng Chen
- Electrochemical Technology Center, Department of Chemistry, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Jacek Lipkowski
- Electrochemical Technology Center, Department of Chemistry, University of Guelph, Guelph, Ontario N1G 2W1, Canada
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Dardelle F, Phelip C, Darabi M, Kondakova T, Warnet X, Combret E, Juranville E, Novikov A, Kerzerho J, Caroff M. Diversity, Complexity, and Specificity of Bacterial Lipopolysaccharide (LPS) Structures Impacting Their Detection and Quantification. Int J Mol Sci 2024; 25:3927. [PMID: 38612737 PMCID: PMC11011966 DOI: 10.3390/ijms25073927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 03/21/2024] [Accepted: 03/23/2024] [Indexed: 04/14/2024] Open
Abstract
Endotoxins are toxic lipopolysaccharides (LPSs), extending from the outer membrane of Gram-negative bacteria and notorious for their toxicity and deleterious effects. The comparison of different LPSs, isolated from various Gram-negative bacteria, shows a global similar architecture corresponding to a glycolipid lipid A moiety, a core oligosaccharide, and outermost long O-chain polysaccharides with molecular weights from 2 to 20 kDa. LPSs display high diversity and specificity among genera and species, and each bacterium contains a unique set of LPS structures, constituting its protective external barrier. Some LPSs are not toxic due to their particular structures. Different, well-characterized, and highly purified LPSs were used in this work to determine endotoxin detection rules and identify their impact on the host. Endotoxin detection is a major task to ensure the safety of human health, especially in the pharma and food sectors. Here, we describe the impact of different LPS structures obtained under different bacterial growth conditions on selective LPS detection methods such as LAL, HEK-blue TLR-4, LC-MS2, and MALDI-MS. In these various assays, LPSs were shown to respond differently, mainly attributable to their lipid A structures, their fatty acid numbers and chain lengths, the presence of phosphate groups, and their possible substitutions.
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Affiliation(s)
- Flavien Dardelle
- LPS-BioSciences, Bâtiment 440, Université de Paris-Saclay, 91400 Orsay, France; (F.D.); (M.D.); (E.J.)
| | - Capucine Phelip
- HEPHAISTOS-Pharma, Bâtiment 440, Université de Paris-Saclay, 91400 Orsay, France; (C.P.); (A.N.); (J.K.)
| | - Maryam Darabi
- LPS-BioSciences, Bâtiment 440, Université de Paris-Saclay, 91400 Orsay, France; (F.D.); (M.D.); (E.J.)
| | - Tatiana Kondakova
- LPS-BioSciences, Bâtiment 440, Université de Paris-Saclay, 91400 Orsay, France; (F.D.); (M.D.); (E.J.)
| | - Xavier Warnet
- LPS-BioSciences, Bâtiment 440, Université de Paris-Saclay, 91400 Orsay, France; (F.D.); (M.D.); (E.J.)
| | - Edyta Combret
- LPS-BioSciences, Bâtiment 440, Université de Paris-Saclay, 91400 Orsay, France; (F.D.); (M.D.); (E.J.)
| | - Eugenie Juranville
- LPS-BioSciences, Bâtiment 440, Université de Paris-Saclay, 91400 Orsay, France; (F.D.); (M.D.); (E.J.)
| | - Alexey Novikov
- HEPHAISTOS-Pharma, Bâtiment 440, Université de Paris-Saclay, 91400 Orsay, France; (C.P.); (A.N.); (J.K.)
| | - Jerome Kerzerho
- HEPHAISTOS-Pharma, Bâtiment 440, Université de Paris-Saclay, 91400 Orsay, France; (C.P.); (A.N.); (J.K.)
| | - Martine Caroff
- LPS-BioSciences, Bâtiment 440, Université de Paris-Saclay, 91400 Orsay, France; (F.D.); (M.D.); (E.J.)
- HEPHAISTOS-Pharma, Bâtiment 440, Université de Paris-Saclay, 91400 Orsay, France; (C.P.); (A.N.); (J.K.)
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Cho J, Hong HW, Park K, Myung H, Yoon H. Unveiling the mechanism of bactericidal activity of a cecropin A-fused endolysin LNT113. Int J Biol Macromol 2024; 260:129493. [PMID: 38224804 DOI: 10.1016/j.ijbiomac.2024.129493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 12/27/2023] [Accepted: 01/12/2024] [Indexed: 01/17/2024]
Abstract
Endolysins are lytic enzymes produced by bacteriophages at the end of their lytic cycle and degrade the peptidoglycan layer of the bacterial cell wall. Thus, they have been extensively explored as a promising antibacterial agent to replace or supplement current antibiotics. Gram-negative bacteria, however, are prone to resist exogenous endolysins owing to their protective outer membrane. We previously engineered endolysin EC340, encoded by the Escherichia coli phage PBEC131, by substituting its seven amino acids and fusing an antimicrobial peptide cecropin A at its N-terminus. The engineered endolysin LNT113 exerted superior activity to its intrinsic form. This study investigated how cecropin A fusion facilitated the bactericidal activity of LNT113 toward Gram-negative bacteria. Cecropin A of LNT113 markedly increased the interaction with lipopolysaccharides, while the E. coli defective in the core oligosaccharide was less susceptible to endolysins, implicating the interaction between the core oligosaccharide and endolysins. In fact, E. coli with compromised lipid A construction was more vulnerable to LNT113 treatment, suggesting that the integrity of the lipid A layer was important to resist the internalization of LNT113 across the outer membrane. Cecropin A fusion further accelerated the inner membrane destabilization, thereby enabling LNT113 to deconstruct it promptly. Owing to the increased membrane permeability, LNT113 could inactivate some Gram-positive bacteria as well. This study demonstrates that cecropin A fusion is a feasible method to improve the membrane permeability of endolysins in both Gram-negative and Gram-positive bacteria.
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Affiliation(s)
- Jeongik Cho
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea
| | | | - Kyungah Park
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea
| | - Heejoon Myung
- LyseNTech Co., Ltd., Seongnam, South Korea; Department of Bioscience and Biotechnology, Hankuk University of Foreign Studies, Yongin, South Korea
| | - Hyunjin Yoon
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea; Department of Applied Chemistry and Biological Engineering, Ajou University, Suwon, South Korea.
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Yang H, Verhoeve VI, Chandler CE, Nallar S, Snyder GA, Ernst RK, Gillespie JJ. Structural determination of Rickettsia lipid A without chemical extraction confirms shorter acyl chains in later-evolving spotted fever group pathogens. mSphere 2024; 9:e0060923. [PMID: 38259062 PMCID: PMC10900879 DOI: 10.1128/msphere.00609-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 12/12/2023] [Indexed: 01/24/2024] Open
Abstract
Rickettsiae are Gram-negative obligate intracellular parasites of numerous eukaryotes. Human pathogens of the transitional group (TRG), typhus group (TG), and spotted fever group (SFG) rickettsiae infect blood-feeding arthropods, have dissimilar clinical manifestations, and possess unique genomic and morphological attributes. Lacking glycolysis, rickettsiae pilfer numerous metabolites from the host cytosol to synthesize peptidoglycan and lipopolysaccharide (LPS). For LPS, O-antigen immunogenicity varies between SFG and TG pathogens; however, lipid A proinflammatory potential is unknown. We previously demonstrated that Rickettsia akari (TRG), Rickettsia typhi (TG), and Rickettsia montanensis (SFG) produce lipid A with long 2' secondary acyl chains (C16 or C18) compared to short 2' secondary acyl chains (C12) in Rickettsia rickettsii (SFG) lipid A. To further probe this structural heterogeneity and estimate a time point when shorter 2' secondary acyl chains originated, we generated lipid A structures for two additional SFG rickettsiae (Rickettsia rhipicephali and Rickettsia parkeri) utilizing fast lipid analysis technique adopted for use with tandem mass spectrometry (FLATn). FLATn allowed analysis of lipid A structure directly from host cell-purified bacteria, providing a substantial improvement over lipid A chemical extraction. FLATn-derived structures indicate SFG rickettsiae diverging after R. rhipicephali evolved shorter 2' secondary acyl chains. While 2' secondary acyl chain lengths do not distinguish Rickettsia pathogens from non-pathogens, in silico analyses of Rickettsia LpxL late acyltransferases revealed discrete active sites and hydrocarbon rulers for long versus short 2' secondary acyl chain addition. Our collective data warrant determining Rickettsia lipid A inflammatory potential and how structural heterogeneity impacts lipid A-host receptor interactions.IMPORTANCEDeforestation, urbanization, and homelessness lead to spikes in Rickettsioses. Vector-borne human pathogens of transitional group (TRG), typhus group (TG), and spotted fever group (SFG) rickettsiae differ by clinical manifestations, immunopathology, genome composition, and morphology. We previously showed that lipid A (or endotoxin), the membrane anchor of Gram-negative bacterial lipopolysaccharide (LPS), structurally differs in Rickettsia rickettsii (later-evolving SFG) relative to Rickettsia montanensis (basal SFG), Rickettsia typhi (TG), and Rickettsia akari (TRG). As lipid A structure influences recognition potential in vertebrate LPS sensors, further assessment of Rickettsia lipid A structural heterogeneity is needed. Here, we sidestepped the difficulty of ex vivo lipid A chemical extraction by utilizing fast lipid analysis technique adopted for use with tandem mass spectrometry, a new procedure for generating lipid A structures directly from host cell-purified bacteria. These data confirm that later-evolving SFG pathogens synthesize structurally distinct lipid A. Our findings impact interpreting immune responses to different Rickettsia pathogens and utilizing lipid A adjuvant or anti-inflammatory properties in vaccinology.
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Affiliation(s)
- Hyojik Yang
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland, USA
| | - Victoria I. Verhoeve
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, Maryland, USA
| | - Courtney E. Chandler
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland, USA
| | - Shreeram Nallar
- Division of Vaccine Research, Institute of Human Virology, University of Maryland, Baltimore, Maryland, USA
| | - Greg A. Snyder
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, Maryland, USA
- Division of Vaccine Research, Institute of Human Virology, University of Maryland, Baltimore, Maryland, USA
| | - Robert K. Ernst
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland, USA
| | - Joseph J. Gillespie
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, Maryland, USA
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Vaiwala R, Ayappa KG. Martini-3 Coarse-Grained Models for the Bacterial Lipopolysaccharide Outer Membrane of Escherichia coli. J Chem Theory Comput 2024; 20:1704-1716. [PMID: 37676287 DOI: 10.1021/acs.jctc.3c00471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
The outer lipopolysaccharide (LPS) membrane of Gram-negative bacteria forms the main barrier for transport of antimicrobial molecules into the bacterial cell. In this study we develop coarse-grained models for the outer membrane of Escherichia coli in the Martini-3 framework. The coarse-grained model force field was parametrized and validated using all-atom simulations of symmetric membranes of lipid A and rough LPS as well as a complete asymmetric membrane of LPS with the O-antigen. The bonded parameters were obtained using an iterative refinement procedure with target bonded distributions obtained from all-atom simulations. The membrane thickness, area of the LPS, and density distributions for the different regions as well as the water and ion densities in Martini-3 simulations show excellent agreement with the all-atom data. Additionally the solvent accessible surface area for individual molecules in water was found to be in good agreement. The binding of calcium ions with phosphate and carboxylate moieties of LPS is accurately captured in the Martini-3 model, indicative of the integrity of the highly negatively charged LPS molecules in the outer membranes of Gram-negative bacteria. The melting transition of the coarse-grained lipid A membrane model was found to occur between 300 and 310 K, and the model captured variations in area per LPS, order parameter, and membrane thickness across the melting transition. Our study reveals that the proposed Martini-3 models for LPS are able to capture the physicochemical balance of the complex sugar architecture of the outer membrane of Escherichia coli. The coarse-grained models developed in this study would be useful for determining membrane protein interactions and permeation of potential antimicrobials through bacterial membranes at mesoscopic spatial and temporal scales.
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Affiliation(s)
- Rakesh Vaiwala
- Department of Chemical Engineering, Indian Institute of Science, Bangalore 560012, India
| | - K Ganapathy Ayappa
- Department of Chemical Engineering, Indian Institute of Science, Bangalore 560012, India
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Vijayakumar S, Swetha RG, Bakthavatchalam YD, Vasudevan K, Abirami Shankar B, Kirubananthan A, Walia K, Ramaiah S, Biswas I, Veeraraghavan B, Anbarasu A. Genomic investigation unveils colistin resistance mechanism in carbapenem-resistant Acinetobacter baumannii clinical isolates. Microbiol Spectr 2024; 12:e0251123. [PMID: 38214512 PMCID: PMC10846133 DOI: 10.1128/spectrum.02511-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 11/29/2023] [Indexed: 01/13/2024] Open
Abstract
Colistin resistance in Acinetobacter baumannii is mediated by multiple mechanisms. Recently, mutations within pmrABC two-component system and overexpression of eptA gene due to upstream insertion of ISAba1 have been shown to play a major role. Thus, the aim of our study is to characterize colistin resistance mechanisms among the clinical isolates of A. baumannii in India. A total of 207 clinical isolates of A. baumannii collected from 2016 to 2019 were included in this study. Mutations within lipid A biosynthesis and pmrABC genes were characterized by whole-genome shotgun sequencing. Twenty-eight complete genomes were further characterized by hybrid assembly approach to study insertional inactivation of lpx genes and the association of ISAba1-eptA. Several single point mutations (SNPs), like M12I in pmrA, A138T and A444V in pmrB, and E117K in lpxD, were identified. We are the first to report two novel SNPs (T7I and V383I) in the pmrC gene. Among the five colistin-resistant A. baumannii isolates where complete genome was available, the analysis showed that three of the five isolates had ISAba1 insertion upstream of eptA. No mcr genes were identified among the isolates. We mapped the SNPs on the respective protein structures to understand the effect on the protein activity. We found that majority of the SNPs had little effect on the putative protein function; however, some SNPs might destabilize the local structure. Our study highlights the diversity of colistin resistance mechanisms occurring in A. baumannii, and ISAba1-driven eptA overexpression is responsible for colistin resistance among the Indian isolates.IMPORTANCEAcinetobacter baumannii is a Gram-negative, emerging and opportunistic bacterial pathogen that is often associated with a wide range of nosocomial infections. The treatment of these infections is hindered by increase in the occurrence of A. baumannii strains that are resistant to most of the existing antibiotics. The current drug of choice to treat the infection caused by A. baumannii is colistin, but unfortunately, the bacteria started to show resistance to the last-resort antibiotic. The loss of lipopolysaccharides and mutations in lipid A biosynthesis genes are the main reasons for the colistin resistance. The present study characterized 207 A. baumannii clinical isolates and constructed complete genomes of 28 isolates to recognize the mechanisms of colistin resistance. We showed the mutations in the colistin-resistant variants within genes essential for lipid A biosynthesis and that cause these isolates to lose the ability to produce lipopolysaccharides.
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Affiliation(s)
- Saranya Vijayakumar
- Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Rayapadi G. Swetha
- Medical and Biological Computing Laboratory, School of Biosciences and Technology, Vellore Institute of Technology (VIT), Vellore, Tamil Nadu, India
| | | | - Karthick Vasudevan
- Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India
- Department of Biotechnology, School of Applied Sciences, REVA University, Bangalore, India
| | - Baby Abirami Shankar
- Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India
| | | | - Kamini Walia
- Division of Epidemiology and Communicable Diseases, Indian Council for Medical Research, New Delhi, India
| | - Sudha Ramaiah
- Medical and Biological Computing Laboratory, School of Biosciences and Technology, Vellore Institute of Technology (VIT), Vellore, Tamil Nadu, India
| | - Indranil Biswas
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas, USA
| | - Balaji Veeraraghavan
- Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Anand Anbarasu
- Medical and Biological Computing Laboratory, School of Biosciences and Technology, Vellore Institute of Technology (VIT), Vellore, Tamil Nadu, India
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10
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Park S, Choi J, Shin D, Kwon KT, Kim SH, Wi YM, Ko KS. Conversion to colistin susceptibility by tigecycline exposure in colistin-resistant Klebsiella pneumoniae and its implications to combination therapy. Int J Antimicrob Agents 2024; 63:107017. [PMID: 37884228 DOI: 10.1016/j.ijantimicag.2023.107017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 10/13/2023] [Accepted: 10/21/2023] [Indexed: 10/28/2023]
Abstract
OBJECTIVES This study investigated the effect of tigecycline exposure on susceptibility of colistin-resistant Klebsiella pneumoniae isolates to colistin and explored the possibility of antibiotic combination at low concentrations to treat colistin-resistant K. pneumoniae isolates. METHODS Twelve tigecycline-resistant (TIR) mutants were induced in vitro from wild-type, colistin-resistant, and tigecycline-susceptible K. pneumoniae isolates. Antibiotic susceptibility was determined using the broth microdilution method. The deduced amino acid alterations were identified for genes associated with colistin resistance, lipid A biosynthesis, and tigecycline resistance. Expression levels of genes were compared between wild-type stains and TIR mutants using quantitative real-time polymerase chain reaction (PCR). Lipid A modification was explored using MALDI-TOF mass spectrometry. Time-killing assay was performed to assess the efficiency of combination therapy using low concentrations of colistin and tigecycline. RESULTS All TIR mutants except one were converted to be susceptible to colistin. These TIR mutants had mutations in the ramR gene and increased expression levels of ramA. Three genes associated with lipid A biosynthesis, lpxC, lpxL, and lpxO, were also overexpressed in TIR mutants, although no mutation was observed. Additional polysaccharides found in colistin-resistant, wild-type strains were modified in TIR mutants. Colistin-resistant K. pneumoniae strains were eliminated in vitro by combining tigecycline and colistin at 2 mg/L. In this study, we found that tigecycline exposure resulted in reduced resistance of colistin-resistant K. pneumoniae to colistin. Such an effect was mediated by regulation of lipid A modification involving ramA and lpx genes. CONCLUSION Because of such reduced resistance, a combination of colistin and tigecycline in low concentrations could effectively eradicate colistin-resistant K. pneumoniae strains.
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Affiliation(s)
- Suyeon Park
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Jihyun Choi
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Dongwoo Shin
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Ki Tae Kwon
- Department of Internal Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Si-Ho Kim
- Division of Infectious Diseases, Department of Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Republic of Korea
| | - Yu Mi Wi
- Division of Infectious Diseases, Department of Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Republic of Korea
| | - Kwan Soo Ko
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea.
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11
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Liang L, Zhong LL, Wang L, Zhou D, Li Y, Li J, Chen Y, Liang W, Wei W, Zhang C, Zhao H, Lyu L, Stoesser N, Doi Y, Bai F, Feng S, Tian GB. A new variant of the colistin resistance gene MCR-1 with co-resistance to β-lactam antibiotics reveals a potential novel antimicrobial peptide. PLoS Biol 2023; 21:e3002433. [PMID: 38091366 PMCID: PMC10786390 DOI: 10.1371/journal.pbio.3002433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 01/12/2024] [Accepted: 11/14/2023] [Indexed: 01/13/2024] Open
Abstract
The emerging and global spread of a novel plasmid-mediated colistin resistance gene, mcr-1, threatens human health. Expression of the MCR-1 protein affects bacterial fitness and this cost correlates with lipid A perturbation. However, the exact molecular mechanism remains unclear. Here, we identified the MCR-1 M6 variant carrying two-point mutations that conferred co-resistance to β-lactam antibiotics. Compared to wild-type (WT) MCR-1, this variant caused severe disturbance in lipid A, resulting in up-regulation of L, D-transpeptidases (LDTs) pathway, which explains co-resistance to β-lactams. Moreover, we show that a lipid A loading pocket is localized at the linker domain of MCR-1 where these 2 mutations are located. This pocket governs colistin resistance and bacterial membrane permeability, and the mutated pocket in M6 enhances the binding affinity towards lipid A. Based on this new information, we also designed synthetic peptides derived from M6 that exhibit broad-spectrum antimicrobial activity, exposing a potential vulnerability that could be exploited for future antimicrobial drug design.
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Affiliation(s)
- Lujie Liang
- Advanced Medical Technology Center, The First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Department of Immunology, School of Medicine, Sun Yat-Sen University, Shenzhen, China
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Lan-Lan Zhong
- Advanced Medical Technology Center, The First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Department of Immunology, School of Medicine, Sun Yat-Sen University, Shenzhen, China
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Lin Wang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, Shanghai Tech University, Shanghai, China
| | - Dianrong Zhou
- Advanced Medical Technology Center, The First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Department of Immunology, School of Medicine, Sun Yat-Sen University, Shenzhen, China
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Yaxin Li
- Advanced Medical Technology Center, The First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Department of Immunology, School of Medicine, Sun Yat-Sen University, Shenzhen, China
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Jiachen Li
- Advanced Medical Technology Center, The First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Department of Immunology, School of Medicine, Sun Yat-Sen University, Shenzhen, China
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Yong Chen
- School of Laboratory Medicine, Chengdu Medical College, Chengdu, China
| | - Wanfei Liang
- Advanced Medical Technology Center, The First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Department of Immunology, School of Medicine, Sun Yat-Sen University, Shenzhen, China
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Wenjing Wei
- Center for Tuberculosis Control of Guangdong Province, Guangzhou, Guangdong, China
| | - Chenchen Zhang
- Center for Tuberculosis Control of Guangdong Province, Guangzhou, Guangdong, China
| | - Hui Zhao
- Laboratory Medicine, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Lingxuan Lyu
- Advanced Medical Technology Center, The First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Department of Immunology, School of Medicine, Sun Yat-Sen University, Shenzhen, China
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Nicole Stoesser
- Modernising Medical Microbiology, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Yohei Doi
- University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology, Fujita Health University School of Medicine, Aichi, Japan
| | - Fang Bai
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, Shanghai Tech University, Shanghai, China
| | - Siyuan Feng
- Advanced Medical Technology Center, The First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Department of Immunology, School of Medicine, Sun Yat-Sen University, Shenzhen, China
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Guo-Bao Tian
- Advanced Medical Technology Center, The First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Department of Immunology, School of Medicine, Sun Yat-Sen University, Shenzhen, China
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
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12
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Hurst MN, Beebout CJ, Hollingsworth A, Guckes KR, Purcell A, Bermudez TA, Williams D, Reasoner SA, Trent MS, Hadjifrangiskou M. The QseB response regulator imparts tolerance to positively charged antibiotics by controlling metabolism and minor changes to LPS. mSphere 2023; 8:e0005923. [PMID: 37676915 PMCID: PMC10597456 DOI: 10.1128/msphere.00059-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 06/02/2023] [Indexed: 09/09/2023] Open
Abstract
The modification of lipopolysaccharide (LPS) in Escherichia coli and Salmonella spp. is primarily controlled by the two-component system PmrAB. LPS modification allows bacteria to avoid killing by positively charged antibiotics like polymyxin B (PMB). We previously demonstrated that in uropathogenic E. coli (UPEC), the sensor histidine kinase PmrB also activates a non-cognate transcription factor, QseB, and this activation somehow augments PMB tolerance in UPEC. Here, we demonstrate-for the first time-that in the absence of the canonical LPS transcriptional regulator, PmrA, QseB can direct some modifications on the LPS. In agreement with this observation, transcriptional profiling analyses demonstrate regulatory overlaps between PmrA and QseB in terms of regulating LPS modification genes. However, both PmrA and QseB must be present for UPEC to mount robust tolerance to PMB. Transcriptional and metabolomic analyses also reveal that QseB transcriptionally regulates the metabolism of glutamate and 2-oxoglutarate, which are consumed and produced during the modification of lipid A. We show that deletion of qseB alters glutamate levels in the bacterial cells. The qseB deletion mutant, which is susceptible to positively charged antibiotics, is rescued by exogenous addition of 2-oxoglutarate. These findings uncover a previously unknown mechanism of metabolic control of antibiotic tolerance that may be contributing to antibiotic treatment failure in the clinic. IMPORTANCE Although antibiotic prescriptions are guided by well-established susceptibility testing methods, antibiotic treatments oftentimes fail. The presented work is significant because it uncovers a mechanism by which bacteria transiently avoid killing by antibiotics. This mechanism involves two closely related transcription factors, PmrA and QseB, which are conserved across Enterobacterales. We demonstrate that PmrA and QseB share regulatory targets in lipid A modification pathway and prove that QseB can orchestrate modifications of lipid A in Escherichia coli in the absence of PmrA. Finally, we show that QseB controls glutamate metabolism during the antibiotic response. These results suggest that rewiring of QseB-mediated metabolic genes could lead to stable antibiotic resistance in subpopulations within the host, thereby contributing to antibiotic treatment failure.
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Affiliation(s)
- Melanie N. Hurst
- Division of Molecular Pathogenesis, Department of Pathology, Microbiology & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Connor J. Beebout
- Division of Molecular Pathogenesis, Department of Pathology, Microbiology & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Alexis Hollingsworth
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Kirsten R. Guckes
- Division of Molecular Pathogenesis, Department of Pathology, Microbiology & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Alexandria Purcell
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Tomas A. Bermudez
- Division of Molecular Pathogenesis, Department of Pathology, Microbiology & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Diamond Williams
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Seth A. Reasoner
- Division of Molecular Pathogenesis, Department of Pathology, Microbiology & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - M. Stephen Trent
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Maria Hadjifrangiskou
- Division of Molecular Pathogenesis, Department of Pathology, Microbiology & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Nashville, Tennessee, USA
- Center for Personalized Microbiology, Department of Pathology, Microbiology & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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13
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Hiramatsu Y, Nishida T, Ota N, Tamaki Y, Nugraha DK, Horiguchi Y. DAT, deacylating autotransporter toxin, from Bordetella parapertussis demyristoylates Gα i GTPases and contributes to cough. Proc Natl Acad Sci U S A 2023; 120:e2308260120. [PMID: 37748060 PMCID: PMC10556565 DOI: 10.1073/pnas.2308260120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 08/28/2023] [Indexed: 09/27/2023] Open
Abstract
The pathogenic bacteria Bordetella pertussis and Bordetella parapertussis cause pertussis (whooping cough) and pertussis-like disease, respectively, both of which are characterized by paroxysmal coughing. We previously reported that pertussis toxin (PTx), which inactivates heterotrimeric GTPases of the Gi family through ADP-ribosylation of their α subunits, causes coughing in combination with Vag8 and lipid A in B. pertussis infection. In contrast, the mechanism of cough induced by B. parapertussis, which produces Vag8 and lipopolysaccharide (LPS) containing lipid A, but not PTx, remained to be elucidated. Here, we show that a toxin we named deacylating autotransporter toxin (DAT) of B. parapertussis inactivates heterotrimeric Gi GTPases through demyristoylation of their α subunits and contributes to cough production along with Vag8 and LPS. These results indicate that DAT plays a role in B. parapertussis infection in place of PTx.
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Affiliation(s)
- Yukihiro Hiramatsu
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka565-0871, Japan
| | - Takashi Nishida
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka565-0871, Japan
| | - Natsuko Ota
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka565-0871, Japan
| | - Yuki Tamaki
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka565-0871, Japan
| | - Dendi K. Nugraha
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka565-0871, Japan
| | - Yasuhiko Horiguchi
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka565-0871, Japan
- Center for Infectious Disease Education and Research, Osaka University, Suita, Osaka565-0871, Japan
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14
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Wang Z, Zhao A, Qiao J, Yu J, He F, Bi Y, Yu L, Wang X. Engineering Escherichia coli MG1655 to Efficiently Produce 3-Deacyl-4'-monophosphoryl Lipid A. J Agric Food Chem 2023; 71:13376-13390. [PMID: 37656614 DOI: 10.1021/acs.jafc.3c00681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/03/2023]
Abstract
Monophosphoryl lipid A, derived from Salmonella minnesota R595, has been used in various adjuvant formulations. Escherichia coli can produce lipid A, but its structure is different. In this study, E. coli MG1655 has been engineered to efficiently produce the monophosphoryl lipid A. First, 126 genes relevant to the biosynthesis of the fimbriae, flagella, and ECA were deleted in MG1655, resulting in WQM027. Second, the genes pldA, mlaA, and mlaC related to the phospholipid transport system, the gene ptsG related to the carbohydrate phosphotransferase system, and the gene eptA encoding phosphoethanolamine transferase for lipid A modification were further deleted from WQM027, resulting in MW020. Third, lpxE from Francisella novicida and pagP and pagL from Salmonella were overexpressed in pFT24, resulting in pTEPL. pTEPL was transformed into MW020, resulting in MW020/pTEPL. Finally, fabI encoding an enoyl-ACP reductase was deleted from the genome of MW020/pTEPL, resulting in MW021/pTEPL. MW021/pTEPL could produce 85.31 mg/L of lipid A species after 26 h of fed-batch fermentation. Mainly two monophosphoryl lipid A species were produced in MW021/pTEPL, one is 3-deacyl-2-acyloxyacyl-4'-monophosphoryl lipid A and the other is 3-deacyl-4'-monophosphoryl lipid A. E. coli MW021/pTEPL constructed in this study could be an ideal host for the industrial production of monophosphoryl lipid A.
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Affiliation(s)
- Zhen Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Aizhen Zhao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jun Qiao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jing Yu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Fenfang He
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yibing Bi
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Letong Yu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xiaoyuan Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
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15
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Zhao J, Cochrane CS, Najeeb J, Gooden D, Sciandra C, Fan P, Lemaitre N, Newns K, Nicholas RA, Guan Z, Thaden JT, Fowler VG, Spasojevic I, Sebbane F, Toone EJ, Duncan C, Gammans R, Zhou P. Preclinical safety and efficacy characterization of an LpxC inhibitor against Gram-negative pathogens. Sci Transl Med 2023; 15:eadf5668. [PMID: 37556556 PMCID: PMC10785772 DOI: 10.1126/scitranslmed.adf5668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 07/20/2023] [Indexed: 08/11/2023]
Abstract
The UDP-3-O-(R-3-hydroxyacyl)-N-acetylglucosamine deacetylase LpxC is an essential enzyme in the biosynthesis of lipid A, the outer membrane anchor of lipopolysaccharide and lipooligosaccharide in Gram-negative bacteria. The development of LpxC-targeting antibiotics toward clinical therapeutics has been hindered by the limited antibiotic profile of reported non-hydroxamate inhibitors and unexpected cardiovascular toxicity observed in certain hydroxamate and non-hydroxamate-based inhibitors. Here, we report the preclinical characterization of a slow, tight-binding LpxC inhibitor, LPC-233, with low picomolar affinity. The compound is a rapid bactericidal antibiotic, unaffected by established resistance mechanisms to commercial antibiotics, and displays outstanding activity against a wide range of Gram-negative clinical isolates in vitro. It is orally bioavailable and efficiently eliminates infections caused by susceptible and multidrug-resistant Gram-negative bacterial pathogens in murine soft tissue, sepsis, and urinary tract infection models. It displays exceptional in vitro and in vivo safety profiles, with no detectable adverse cardiovascular toxicity in dogs at 100 milligrams per kilogram. These results establish the feasibility of developing oral LpxC-targeting antibiotics for clinical applications.
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Affiliation(s)
- Jinshi Zhao
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | | | - Javaria Najeeb
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
- Current address: Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - David Gooden
- Department of Chemistry, Duke University, Durham, NC 27708, USA
- Small Molecule Synthesis Facility, Duke University, Durham, NC 27708, USA
| | - Carly Sciandra
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Ping Fan
- Pharmacokinetics/Pharmacodynamics (PK/PD) Core Laboratory, Duke Cancer Institute, Durham, NC 27710, USA
| | - Nadine Lemaitre
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR9017-CIIL-Centre d’Infection et d’Immunité de Lille, Lille, France
| | - Kate Newns
- Departments of Pharmacology and Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
- Current address: Envision Pharma Group, Philadelphia, PA 19109, USA
| | - Robert A. Nicholas
- Departments of Pharmacology and Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Ziqiang Guan
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Joshua T. Thaden
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Vance G. Fowler
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Ivan Spasojevic
- Pharmacokinetics/Pharmacodynamics (PK/PD) Core Laboratory, Duke Cancer Institute, Durham, NC 27710, USA
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Florent Sebbane
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR9017-CIIL-Centre d’Infection et d’Immunité de Lille, Lille, France
| | - Eric J. Toone
- Department of Chemistry, Duke University, Durham, NC 27708, USA
- Current address: Breakthrough Energy Ventures, 4110 Carillon Point Kirkland, WA 98033 USA
| | | | | | - Pei Zhou
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
- Department of Chemistry, Duke University, Durham, NC 27708, USA
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16
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Borio A, Holgado A, Passegger C, Strobl H, Beyaert R, Heine H, Zamyatina A. Exploring Species-Specificity in TLR4/MD-2 Inhibition with Amphiphilic Lipid A Mimicking Glycolipids. Molecules 2023; 28:5948. [PMID: 37630200 PMCID: PMC10459247 DOI: 10.3390/molecules28165948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 07/28/2023] [Accepted: 08/01/2023] [Indexed: 08/27/2023] Open
Abstract
The Toll-like receptor 4 (TLR4)/myeloid differentiation factor 2 (MD-2) complex is a key receptor of the innate immune system and a major driver of inflammation that is responsible for the multifaceted defense response to Gram-negative infections. However, dysfunction in the tightly regulated mechanisms of TLR4-mediated signaling leads to the uncontrolled upregulation of local and systemic inflammation, often resulting in acute or chronic disease. Therefore, the TLR4/MD-2 receptor complex is an attractive target for the design and development of anti-inflammatory therapies which aim to control the unrestrained activation of TLR4-mediated signaling. Complex structure-activity relationships and species-specificity behind ligand recognition by the TLR4/MD-2 complex complicate the development of MD-2-specific TLR4 antagonists. The restriction of the conformational flexibility of the disaccharide polar head group is one of the key structural features of the newly developed lipid A-mimicking glycophospholipids, which are potential inhibitors of TLR4-mediated inflammation. Since phosphorylation has a crucial influence on MD-2-ligand interaction, glycolipids with variable numbers and positioning of phosphate groups were synthesized and evaluated for their ability to inhibit TLR4-mediated pro-inflammatory signaling in human and murine immune cells. A bis-phosphorylated glycolipid was found to have nanomolar antagonist activity on human TLR4 while acting as a partial agonist on murine TLR4. The glycolipid inhibited mTLR4/MD-2-mediated cytokine release, acting as an antagonist in the presence of lipopolysaccharide (LPS), but at the same time induced low-level cytokine production.
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Affiliation(s)
- Alessio Borio
- Institute of Organic Chemistry, Department of Chemistry, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Aurora Holgado
- Unit of Molecular Signal Transduction in Inflammation, VIB-UGent Center for Inflammation Research, Department for Biomedical Molecular Biology, Ghent University, Technologiepark 71, B-9052 Ghent, Belgium
| | - Christina Passegger
- Division of Immunology and Pathophysiology, Medical University Graz, Heinrichstraße 31, 8010 Graz, Austria
| | - Herbert Strobl
- Division of Immunology and Pathophysiology, Medical University Graz, Heinrichstraße 31, 8010 Graz, Austria
| | - Rudi Beyaert
- Unit of Molecular Signal Transduction in Inflammation, VIB-UGent Center for Inflammation Research, Department for Biomedical Molecular Biology, Ghent University, Technologiepark 71, B-9052 Ghent, Belgium
| | - Holger Heine
- Research Group Innate Immunity, Priority Area Chronic Lung Diseases, Research Center Borstel, Leibniz Lung Center, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Parkallee 22, 23845 Borstel, Germany
| | - Alla Zamyatina
- Institute of Organic Chemistry, Department of Chemistry, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
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17
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Tamborrini M, Schäfer A, Hauser J, Zou L, Paris DH, Pluschke G. The malaria blood stage antigen PfCyRPA formulated with the TLR-4 agonist adjuvant GLA-SE elicits parasite growth inhibitory antibodies in experimental animals. Malar J 2023; 22:210. [PMID: 37454145 DOI: 10.1186/s12936-023-04638-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 07/01/2023] [Indexed: 07/18/2023] Open
Abstract
BACKGROUND Plasmodium falciparum cysteine-rich protective antigen (PfCyRPA) is an invasion complex protein essential for erythrocyte invasion. In contrast to several previously clinically tested merozoite vaccine candidate antigens, PfCyRPA is not polymorphic, making it a promising candidate antigen for blood stage vaccine development. METHODS Mice and rabbits were immunized with vaccine formulations of recombinantly expressed PfCyRPA adjuvanted either with the glucopyranosyl lipid A (GLA) containing adjuvants GLA-LSQ, GLA-SE, GLA-Alum or with Nanoalum. ELISA and indirect immunofluorescence assays (IFA) were used to analyse elicited IgG titers and the P. falciparum growth inhibitory activity was determined with a standardized in vitro [3H]-hypoxanthine incorporation assay. RESULTS In the mouse experiments, the GLA adjuvanted formulations were superior to the Nanoalum formulation with respect to antibody titer development, IFA sero-conversion rates and in vitro parasite growth-inhibitory activity. In rabbits, the highest titers of parasite growth inhibitory antibodies were obtained with the GLA-SE formulation. Comparable mean ELISA IgG endpoint titers were reached in rabbits after three immunizations with GLA-SE adjuvanted PfCyRPA doses of 5, 25 and 100 µg, but with 100 µg of antigen, only two immunizations were required to reach this titer. CONCLUSION PfCyRPA formulated with the human-compatible adjuvant GLA-SE represents an attractive vaccine candidate for early clinical testing in a controlled P. falciparum blood stage challenge trial.
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Affiliation(s)
- Marco Tamborrini
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Petersplatz 1, 4001, Basel, Switzerland
| | - Anja Schäfer
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Petersplatz 1, 4001, Basel, Switzerland
| | - Julia Hauser
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Petersplatz 1, 4001, Basel, Switzerland
| | - Linghui Zou
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Petersplatz 1, 4001, Basel, Switzerland
| | - Daniel H Paris
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Petersplatz 1, 4001, Basel, Switzerland
| | - Gerd Pluschke
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland.
- University of Basel, Petersplatz 1, 4001, Basel, Switzerland.
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18
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Frantz R, Gwozdzinski K, Gisch N, Doijad SP, Hudel M, Wille M, Abu Mraheil M, Schwudke D, Imirzalioglu C, Falgenhauer L, Ehrmann M, Chakraborty T. A Single Residue within the MCR-1 Protein Confers Anticipatory Resilience. Microbiol Spectr 2023; 11:e0359222. [PMID: 37071007 PMCID: PMC10269488 DOI: 10.1128/spectrum.03592-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 03/21/2023] [Indexed: 04/19/2023] Open
Abstract
The envelope stress response (ESR) of Gram-negative enteric bacteria senses fluctuations in nutrient availability and environmental changes to avert damage and promote survival. It has a protective role toward antimicrobials, but direct interactions between ESR components and antibiotic resistance genes have not been demonstrated. Here, we report interactions between a central regulator of ESR viz., the two-component signal transduction system CpxRA (conjugative pilus expression), and the recently described mobile colistin resistance protein (MCR-1). Purified MCR-1 is specifically cleaved within its highly conserved periplasmic bridge element, which links its N-terminal transmembrane domain with the C-terminal active-site periplasmic domain, by the CpxRA-regulated serine endoprotease DegP. Recombinant strains harboring cleavage site mutations in MCR-1 are either protease resistant or degradation susceptible, with widely differing consequences for colistin resistance. Transfer of the gene encoding a degradation-susceptible mutant to strains that lack either DegP or its regulator CpxRA restores expression and colistin resistance. MCR-1 production in Escherichia coli imposes growth restriction in strains lacking either DegP or CpxRA, effects that are reversed by transactive expression of DegP. Excipient allosteric activation of the DegP protease specifically inhibits growth of isolates carrying mcr-1 plasmids. As CpxRA directly senses acidification, growth of strains at moderately low pH dramatically increases both MCR-1-dependent phosphoethanolamine (PEA) modification of lipid A and colistin resistance levels. Strains expressing MCR-1 are also more resistant to antimicrobial peptides and bile acids. Thus, a single residue external to its active site induces ESR activity to confer resilience in MCR-1-expressing strains to commonly encountered environmental stimuli, such as changes in acidity and antimicrobial peptides. Targeted activation of the nonessential protease DegP can lead to the elimination of transferable colistin resistance in Gram-negative bacteria. IMPORTANCE The global presence of transferable mcr genes in a wide range of Gram-negative bacteria from clinical, veterinary, food, and aquaculture environments is disconcerting. Its success as a transmissible resistance factor remains enigmatic, because its expression imposes fitness costs and imparts only moderate levels of colistin resistance. Here, we show that MCR-1 triggers regulatory components of the envelope stress response, a system that senses fluctuations in nutrient availability and environmental changes, to promote bacterial survival in low pH environments. We identify a single residue within a highly conserved structural element of mcr-1 distal to its catalytic site that modulates resistance activity and triggers the ESR. Using mutational analysis, quantitative lipid A profiling and biochemical assays, we determined that growth in low pH environments dramatically increases colistin resistance levels and promotes resistance to bile acids and antimicrobial peptides. We exploited these findings to develop a targeted approach that eliminates mcr-1 and its plasmid carriers.
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Affiliation(s)
- Renate Frantz
- Institute of Medical Microbiology, Justus Liebig University Giessen, Giessen, Germany
- German Center for Infection Research, Partner Site: Giessen-Marburg-Langen, Giessen, Germany
| | - Konrad Gwozdzinski
- Institute of Medical Microbiology, Justus Liebig University Giessen, Giessen, Germany
- German Center for Infection Research, Partner Site: Giessen-Marburg-Langen, Giessen, Germany
| | - Nicolas Gisch
- Division of Bioanalytical Chemistry, Priority Area Infections, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Swapnil Prakash Doijad
- Institute of Medical Microbiology, Justus Liebig University Giessen, Giessen, Germany
- German Center for Infection Research, Partner Site: Giessen-Marburg-Langen, Giessen, Germany
| | - Martina Hudel
- Institute of Medical Microbiology, Justus Liebig University Giessen, Giessen, Germany
| | - Maria Wille
- Institute of Hygiene and Environmental Medicine, Justus Liebig University Giessen, Giessen, Germany
| | - Mobarak Abu Mraheil
- Institute of Medical Microbiology, Justus Liebig University Giessen, Giessen, Germany
| | - Dominik Schwudke
- Division of Bioanalytical Chemistry, Priority Area Infections, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
- German Center for Infection Research, Partner Site: Hamburg-Lübeck-Borstel-Riems, Borstel, Germany
- Airway Research Center North, Partner Site: Research Center Borstel, Borstel, Germany
| | - Can Imirzalioglu
- Institute of Medical Microbiology, Justus Liebig University Giessen, Giessen, Germany
- Hessian University Competence Center for Hospital Hygiene, Justus Liebig University Giessen, Giessen, Germany
- German Center for Infection Research, Partner Site: Giessen-Marburg-Langen, Giessen, Germany
| | - Linda Falgenhauer
- Institute of Hygiene and Environmental Medicine, Justus Liebig University Giessen, Giessen, Germany
- Hessian University Competence Center for Hospital Hygiene, Justus Liebig University Giessen, Giessen, Germany
- German Center for Infection Research, Partner Site: Giessen-Marburg-Langen, Giessen, Germany
| | - Michael Ehrmann
- Center of Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Essen, Germany
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Trinad Chakraborty
- Institute of Medical Microbiology, Justus Liebig University Giessen, Giessen, Germany
- Hessian University Competence Center for Hospital Hygiene, Justus Liebig University Giessen, Giessen, Germany
- German Center for Infection Research, Partner Site: Giessen-Marburg-Langen, Giessen, Germany
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19
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De Nicola A, Montis C, Donati G, Molinaro A, Silipo A, Balestri A, Berti D, Di Lorenzo F, Zhu YL, Milano G. Bacterial lipids drive compartmentalization on the nanoscale. Nanoscale 2023; 15:8988-8995. [PMID: 37144495 PMCID: PMC10210972 DOI: 10.1039/d3nr00559c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 04/21/2023] [Indexed: 05/06/2023]
Abstract
The design of cellular functions in synthetic systems, inspired by the internal partitioning of living cells, is a constantly growing research field that is paving the way to a large number of new remarkable applications. Several hierarchies of internal compartments like polymersomes, liposomes, and membranes are used to control the transport, release, and chemistry of encapsulated species. However, the experimental characterization and the comprehension of glycolipid mesostructures are far from being fully addressed. Lipid A is indeed a glycolipid and the endotoxic part of Gram-negative bacterial lipopolysaccharide; it is the moiety that is recognized by the eukaryotic receptors giving rise to the modulation of innate immunity. Herein we propose, for the first time, a combined approach based on hybrid Particle-Field (hPF) Molecular Dynamics (MD) simulations and Small Angle X-Ray Scattering (SAXS) experiments to gain a molecular picture of the complex supramolecular structures of lipopolysaccharide (LPS) and lipid A at low hydration levels. The mutual support of data from simulations and experiments allowed the unprecedented discovery of the presence of a nano-compartmentalized phase composed of liposomes of variable size and shape which can be used in synthetic biological applications.
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Affiliation(s)
- Antonio De Nicola
- Scuola Superiore Meridionale, Via Largo San Marcellino 10, 80132 Napoli, Italy
- Graduate School of Organic Materials Science, Yamagata, University, Jonan 4-3-16, Yonezawa, Yamagata, 992-8510, Japan
| | - Costanza Montis
- Dipartimento di Chimica "Ugo Schiff", Università degli Studi di Firenze and CSGI, 50019 Firenze, Italy.
| | - Greta Donati
- Department of Chemistry and Biology, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy
| | - Antonio Molinaro
- Department of Chemical Sciences, University of Napoli Federico II, Complesso Universitario Monte Santangelo, Via Cintia 4, 80126 Napoli, Italy.
| | - Alba Silipo
- Department of Chemical Sciences, University of Napoli Federico II, Complesso Universitario Monte Santangelo, Via Cintia 4, 80126 Napoli, Italy.
| | - Arianna Balestri
- Dipartimento di Chimica "Ugo Schiff", Università degli Studi di Firenze and CSGI, 50019 Firenze, Italy.
| | - Debora Berti
- Dipartimento di Chimica "Ugo Schiff", Università degli Studi di Firenze and CSGI, 50019 Firenze, Italy.
| | - Flaviana Di Lorenzo
- Department of Chemical Sciences, University of Napoli Federico II, Complesso Universitario Monte Santangelo, Via Cintia 4, 80126 Napoli, Italy.
| | - You-Liang Zhu
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130021, China
| | - Giuseppe Milano
- University of Naples Federico II, Department of Chemical, Materials and Production Engineering, Piazzale V. Tecchio, 80, 80125 Napoli, Italy.
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20
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Wu S, Zhang C, Wang Y, Li P, Du X, Wang X. Dissecting the species-specific recognition of Neoseptin 3 by TLR4/MD2 via molecular dynamics simulations. Phys Chem Chem Phys 2023; 25:13012-13018. [PMID: 37102696 DOI: 10.1039/d3cp00949a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Toll-like receptor 4 (TLR4) is crucial in the innate immune response with species-specific recognition. As a novel small-molecule agonist for mouse TLR4/MD2, Neoseptin 3 fails to activate human TLR4/MD2, while the underlying mechanism is unclear. Herein, molecular dynamics simulations were performed to investigate the species-specific molecular recognition of Neoseptin 3. Lipid A, a classic TLR4 agonist showing no apparent species-specific sensing by TLR4/MD2, was also investigated for comparison. Neoseptin 3 and lipid A showed similar binding patterns with mouse TLR4/MD2. Although the binding free energies of Neoseptin 3 interacting with TLR4/MD2 from mouse and human species were similar, protein-ligand interactions and the details of the dimerization interface were substantially different between Neoseptin 3-bound mouse and human heterotetramers at the atomic level. Neoseptin 3 binding made human (TLR4/MD2)2 more flexible than human (TLR4/MD2/Lipid A)2, especially at the TLR4 C-terminus and MD2, which drives human (TLR4/MD2)2 fluctuating away from the active conformation. In contrast to mouse (TLR4/MD2/2*Neoseptin 3)2 and mouse/human (TLR4/MD2/Lipid A)2 systems, Neoseptin 3 binding to human TLR4/MD2 led to the separating trend of the C-terminus of TLR4. Furthermore, the protein-protein interactions at the dimerization interface between TLR4 and the neighboring MD2 in the human (TLR4/MD2/2*Neoseptin 3)2 system were much weaker than those of the lipid A-bound human TLR4/MD2 heterotetramer. These results explained the inability of Neoseptin 3 to activate human TLR4 signaling and accounted for the species-specific activation of TLR4/MD2, which provides insight for transforming Neoseptin 3 as a human TLR4 agonist.
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Affiliation(s)
- Siru Wu
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China.
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Cong Zhang
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China.
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Yibo Wang
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China.
| | - Penghui Li
- Shenzhen Key Laboratory of Marine Biotechnology and Ecology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, Guangdong, 518060, China
| | - Xiubo Du
- Shenzhen Key Laboratory of Marine Biotechnology and Ecology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, Guangdong, 518060, China
| | - Xiaohui Wang
- Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China.
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, China
- Beijing National Laboratory for Molecular Sciences, Beijing, 100190, China
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21
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Zeng X, Hinenoya A, Guan Z, Xu F, Lin J. Critical role of the RpoE stress response pathway in polymyxin resistance of Escherichia coli. J Antimicrob Chemother 2023; 78:732-746. [PMID: 36658759 PMCID: PMC10396327 DOI: 10.1093/jac/dkad003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 12/31/2022] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVES Polymyxins, including colistin, are the drugs of last resort to treat MDR bacterial infections in humans. In-depth understanding of the molecular basis and regulation of polymyxin resistance would provide new therapeutic opportunities to combat increasing polymyxin resistance. Here we aimed to identify novel targets that are crucial for polymyxin resistance using Escherichia coli BL21(DE3), a unique colistin-resistant model strain. METHODS BL21(DE3) was subjected to random transposon mutagenesis for screening colistin-susceptible mutants. The insertion sites of desired mutants were mapped; the key genes of interest were also inactivated in different strains to examine functional conservation. Specific genes in the known PmrAB and PhoPQ regulatory network were inactivated to examine crosstalk among different pathways. Lipid A species and membrane phospholipids were analysed by normal phase LC/MS. RESULTS Among eight mutants with increased susceptibility to colistin, five mutants contained different mutations in three genes (rseP, degS and surA) that belong to the RpoE stress response pathway. Inactivation of rpoE, pmrB, eptA or pmrD led to significantly increased susceptibility to colistin; however, inactivation of phoQ or eptB did not change colistin MIC. RpoE mutation in different E. coli and Salmonella resistant strains all led to significant reduction in colistin MIC (16-32-fold). Inactivation of rpoE did not change the lipid A profile but significantly altered the phospholipid profile. CONCLUSIONS Inactivation of the important members of the RpoE regulon in polymyxin-resistant strains led to a drastic reduction in polymyxin MIC and an increase of lysophospholipids with no change in lipid A modifications.
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Affiliation(s)
- Ximin Zeng
- Department of Animal Science, The University of Tennessee, Knoxville, TN, USA
| | - Atsushi Hinenoya
- Department of Animal Science, The University of Tennessee, Knoxville, TN, USA
- Graduate School of Veterinary Science, Osaka Metropolitan University, Osaka, Japan
- Asian Health Science Research Institute, Osaka Metropolitan University, Osaka, Japan
- Osaka International Research Center for Infectious Diseases, Osaka Metropolitan University, Osaka, Japan
| | - Ziqiang Guan
- Department of Biochemistry, Duke University Medical Center, Durham, NC, USA
| | - Fuzhou Xu
- Department of Animal Science, The University of Tennessee, Knoxville, TN, USA
- Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Jun Lin
- Department of Animal Science, The University of Tennessee, Knoxville, TN, USA
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22
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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. J Am Soc Mass Spectrom 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] [What about the content of this article? (0)] [Affiliation(s)] [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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23
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Sherman ME, Smith RD, Gardner FM, Goodlett DR, Ernst RK. A Sensitive GC-MS Method for Quantitation of Lipid A Backbone Components and Terminal Phosphate Modifications. J Am Soc Mass Spectrom 2022; 33:2301-2309. [PMID: 36326685 PMCID: PMC9933694 DOI: 10.1021/jasms.2c00266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Lipid A, the hydrophobic anchor of lipopolysaccharide (LPS) present in the outer membrane of Gram-negative bacteria, serves as a target for cationic antimicrobial peptides, such as polymyxins. Membrane stress from polymyxins results in activation of two-component regulatory systems that produce lipid A modifying enzymes. These enzymes add neutral moieties, such as aminoarabinose (AraN) and ethanolamine (EtN) to lipid A terminal phosphates that mask the phosphate's negative charge and inhibit electrostatic interaction with the cationic polymyxins. Currently, these modifications may be detected by MALDI-TOF MS; however, this analysis is only semiquantitative. Herein we describe a GC-MS method to quantitate lipid A backbone components, glucosamine (GlcN) and inorganic phosphate (Pi), along with terminal phosphate modifications AraN and EtN. In this assay, lipid A is isolated from Gram-negative bacterial samples, hydrolyzed into its individual moieties, and derivatized via methoximation followed by silylation prior to analysis via GC-MS. Changes in AraN and EtN quantity were characterized using a variety of regulatory mutants of Salmonella, revealing differences that were not detected using MALDI-TOF MS analysis. Additionally, an increase in the abundance of AraN and EtN modifications were observed when resistant Enterobacter and Escherichia coli strains were grown in the presence of colistin (polymyxin E). Lastly, increased levels of Pi were found in bisphosphorylated lipid A compared to monophosphorylated lipid A samples. Because lipid A modifications serve as indicators of polymyxin resistance in Gram-negative bacteria, this method provides the capacity to monitor polymyxin resistance by quantification of lipid A modification using GC-MS.
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Affiliation(s)
- Matthew E Sherman
- Department of Microbial Pathogenesis, University of Maryland─Baltimore, Baltimore, Maryland 21201, United States
| | - Richard D Smith
- Department of Microbial Pathogenesis, University of Maryland─Baltimore, Baltimore, Maryland 21201, United States
| | - Francesca M Gardner
- Department of Microbial Pathogenesis, University of Maryland─Baltimore, Baltimore, Maryland 21201, United States
| | - David R Goodlett
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada
- University of Gdansk, International Centre for Cancer Vaccine Science, Gdansk, 80-210, Poland
| | - Robert K Ernst
- Department of Microbial Pathogenesis, University of Maryland─Baltimore, Baltimore, Maryland 21201, United States
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24
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Liu S, Wei T, Lu H, Liu X, Shi Y, Chen Q. Interactions between Mannosylerythritol Lipid-A and Heat-Induced Soy Glycinin Aggregates: Physical and Chemical Characteristics, Functional Properties, and Structural Effects. Molecules 2022; 27:molecules27217393. [PMID: 36364220 PMCID: PMC9657017 DOI: 10.3390/molecules27217393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 10/23/2022] [Accepted: 10/24/2022] [Indexed: 11/06/2022] Open
Abstract
Protein-surfactant interactions have a significant influence on food functionality, which has attracted increasing attention. Herein, the effect of glycolipid mannosylerythritol lipid-A (MEL-A) on the heat-induced soy glycinin (11S) aggregates was investigated by measuring the structure, binding properties, interfacial behaviors, and emulsification characteristics of the aggregates. The results showed that MEL-A led to a decrease in the surface tension, viscoelasticity, and foaming ability of the 11S aggregates. In addition, MEL-A with a concentration above critical micelle concentration (CMC) reduced the random aggregation of 11S protein after heat treatment, thus facilitating the formation of self-assembling core-shell particles composed of a core of 11S aggregates covered by MEL-A shells. Infrared spectroscopy, circular dichroism spectroscopy, fluorescence spectroscopy, and isothermal titration calorimetry also confirmed that the interaction forces between MEL-A and 11S were driven by hydrophobic interactions between the exposed hydrophobic groups of the protein and the fatty acid chains or acetyl groups of MEL-A, as well as the hydrogen bonding between mannosyl-D-erythritol groups of MEL-A and amino acids of 11S. The findings of this study indicated that such molecular interactions are responsible for the change in surface behavior and the enhancement of foaming stability and emulsifying property of 11S aggregates upon heat treatment.
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Affiliation(s)
| | | | | | | | - Ying Shi
- Correspondence: (Y.S.); (Q.C.); Tel.: +86-139-6717-1522 (Q.C.)
| | - Qihe Chen
- Correspondence: (Y.S.); (Q.C.); Tel.: +86-139-6717-1522 (Q.C.)
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25
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Galazzo L, Meier G, Januliene D, Parey K, De Vecchis D, Striednig B, Hilbi H, Schäfer LV, Kuprov I, Moeller A, Bordignon E, Seeger MA. The ABC transporter MsbA adopts the wide inward-open conformation in E. coli cells. Sci Adv 2022; 8:eabn6845. [PMID: 36223470 PMCID: PMC9555771 DOI: 10.1126/sciadv.abn6845] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 08/24/2022] [Indexed: 05/28/2023]
Abstract
Membrane proteins are currently investigated after detergent extraction from native cellular membranes and reconstitution into artificial liposomes or nanodiscs, thereby removing them from their physiological environment. However, to truly understand the biophysical properties of membrane proteins in a physiological environment, they must be investigated within living cells. Here, we used a spin-labeled nanobody to interrogate the conformational cycle of the ABC transporter MsbA by double electron-electron resonance. Unexpectedly, the wide inward-open conformation of MsbA, commonly considered a nonphysiological state, was found to be prominently populated in Escherichia coli cells. Molecular dynamics simulations revealed that extensive lateral portal opening is essential to provide access of its large natural substrate core lipid A to the binding cavity. Our work paves the way to investigate the conformational landscape of membrane proteins in cells.
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Affiliation(s)
- Laura Galazzo
- Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44801 Bochum, Germany
- Department of Physical Chemistry, University of Geneva, 1211 Geneva, Switzerland
| | - Gianmarco Meier
- Institute of Medical Microbiology, University of Zurich, 8006 Zurich, Switzerland
| | - Dovile Januliene
- Department of Structural Biology, Osnabrück University, 49076 Osnabrück, Germany
| | - Kristian Parey
- Department of Structural Biology, Osnabrück University, 49076 Osnabrück, Germany
| | - Dario De Vecchis
- Center for Theoretical Chemistry, Ruhr University Bochum, 44801 Bochum, Germany
| | - Bianca Striednig
- Institute of Medical Microbiology, University of Zurich, 8006 Zurich, Switzerland
| | - Hubert Hilbi
- Institute of Medical Microbiology, University of Zurich, 8006 Zurich, Switzerland
| | - Lars V. Schäfer
- Center for Theoretical Chemistry, Ruhr University Bochum, 44801 Bochum, Germany
| | - Ilya Kuprov
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK
| | - Arne Moeller
- Department of Structural Biology, Osnabrück University, 49076 Osnabrück, Germany
| | - Enrica Bordignon
- Faculty of Chemistry and Biochemistry, Ruhr University Bochum, 44801 Bochum, Germany
- Department of Physical Chemistry, University of Geneva, 1211 Geneva, Switzerland
| | - Markus A. Seeger
- Institute of Medical Microbiology, University of Zurich, 8006 Zurich, Switzerland
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Abstract
We describe an innovative use for the recently reported fast lipid analysis technique (FLAT) that allows for the generation of MALDI tandem mass spectrometry data suitable for lipid A structure analysis directly from a single Gram-negative bacterial colony. We refer to this tandem MS version of FLAT as FLATn. Neither technique requires sophisticated sample preparation beyond the selection of a single bacterial colony, which significantly reduces overall analysis time (∼1 h), as compared to conventional methods. Moreover, the tandem mass spectra generated by FLATn provides comprehensive information on fragments of lipid A, for example, ester bonded acyl chain dissociations, cross-ring cleavages, and glycosidic bond dissociations, all of which allow the facile determination of novel lipid A structures or confirmation of expected structures. In addition to generating tandem mass spectra directly from single colonies, we also show that FLATn can be used to analyze lipid A structures taken directly from a complex biological clinical sample without the need for ex vivo growth. From a urine sample from a patient with an E. coli infection, FLATn identified the organism and demonstrated that this clinical isolate carried the mobile colistin resistance-1 gene (mcr-1) that results in the addition of a phosphoethanolamine moiety and subsequently resistance to the antimicrobial, colistin (polymyxin E). Moreover, FLATn allowed for the determination of the existence of a structural isomer in E. coli lipid A that had either a 1- or 4'-phosphate group modification by phosphoethanolamine generated by a change of bacterial culture conditions.
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Affiliation(s)
- Hyojik Yang
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD 21201 USA
| | - Richard D. Smith
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD 21201 USA
- Department of Pathology, School of Medicine, University of Maryland, Baltimore, MD 21201 USA
| | - Courtney E. Chandler
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD 21201 USA
| | - J. Kristie Johnson
- Department of Pathology, School of Medicine, University of Maryland, Baltimore, MD 21201 USA
| | - Shelley N. Jackson
- Translational Analytical Core, NIDA IRP, NIH, Biomedical Research Center, 251 Bayview Boulevard, Suite 200, Room 01B216, Baltimore, MD 21224, USA
| | - Amina S. Woods
- Structural Biology Core, NIDA IRP, NIH, 333 Cassell Drive, Room 1120, Baltimore, MD 21224, USA
- Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine. Baltimore, MD 21205 USA
| | - Alison J. Scott
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD 21201 USA
- Maastricht MultiModal Molecular Imaging (M4I) Institute, Maastricht University, Maastricht 6229 ER, Netherlands
| | - David R. Goodlett
- Department of Biochemistry and Microbiology, University of Victoria, 3800 Finnerty Road. Victoria, BC V8P 5C2, Canada
- International Centre for Cancer Vaccine Science, University of Gdańsk, ul. Kładki 24 80-822 Gdańsk, Poland
| | - Robert K. Ernst
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD 21201 USA
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Schmidinger B, Petri K, Lettl C, Li H, Namineni S, Ishikawa-Ankerhold H, Jiménez-Soto LF, Haas R. Helicobacter pylori binds human Annexins via Lipopolysaccharide to interfere with Toll-like Receptor 4 signaling. PLoS Pathog 2022; 18:e1010326. [PMID: 35176125 PMCID: PMC8890734 DOI: 10.1371/journal.ppat.1010326] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 03/02/2022] [Accepted: 01/31/2022] [Indexed: 12/19/2022] Open
Abstract
Helicobacter pylori colonizes half of the global population and causes gastritis, peptic ulcer disease or gastric cancer. In this study, we were interested in human annexin (ANX), which comprises a protein family with diverse and partly unknown physiological functions, but with a potential role in microbial infections and possible involvement in gastric cancer. We demonstrate here for the first time that H. pylori is able to specifically bind ANXs. Binding studies with purified H. pylori LPS and specific H. pylori LPS mutant strains indicated binding of ANXA5 to lipid A, which was dependent on the lipid A phosphorylation status. Remarkably, ANXA5 binding almost completely inhibited LPS-mediated Toll-like receptor 4- (TLR4) signaling in a TLR4-specific reporter cell line. Furthermore, the interaction is relevant for gastric colonization, as a mouse-adapted H. pylori increased its ANXA5 binding capacity after gastric passage and its ANXA5 incubation in vitro interfered with TLR4 signaling. Moreover, both ANXA2 and ANXA5 levels were upregulated in H. pylori-infected human gastric tissue, and H. pylori can be found in close association with ANXs in the human stomach. Furthermore, an inhibitory effect of ANXA5 binding for CagA translocation could be confirmed. Taken together, our results highlight an adaptive ability of H. pylori to interact with the host cell factor ANX potentially dampening innate immune recognition. H. pylori is very well adapted to its natural habitat, the human gastric mucosa. For this purpose, the bacterium has evolved a number of highly specific virulence factors, such as the cag-type IV secretion system, vacuolating cytotoxin A (VacA) or secreted gamma-glutamyl transpeptidase. An important function of these bacterial factors is to manipulate the host immune response to enable a chronic H. pylori infection. The present work identifies a new player in this process. Here, we have discovered that H. pylori, as well as several other bacterial species, can bind human annexins (ANX), suggesting a more widespread phenomenon. We show that H. pylori specifically binds ANXA5 via lipid A. The interaction is strictly dependent on calcium and modulated by the phosphorylation status of lipid A. Notably, ANXA5 binding strongly inhibits LPS-mediated Toll-like receptor 4 (TLR4) signal transduction, suggesting that H. pylori exploits ANXs binding to avoid its recognition by this important receptor of the innate immune system. The study thus provides novel molecular and mechanistic insights into a further strategy of H. pylori to successfully evade recognition by the host.
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Affiliation(s)
- Barbara Schmidinger
- Chair of Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, Faculty of Medicine, LMU Munich, Germany
| | - Kristina Petri
- Chair of Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, Faculty of Medicine, LMU Munich, Germany
| | - Clara Lettl
- Chair of Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, Faculty of Medicine, LMU Munich, Germany
| | - Hong Li
- West China Marshall Research Center for Infectious Diseases, Center of Infectious Diseases, Division of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Sukumar Namineni
- Chair of Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, Faculty of Medicine, LMU Munich, Germany
| | - Hellen Ishikawa-Ankerhold
- Department of Internal Medicine I, Faculty of Medicine, LMU Munich, Germany
- Walter Brendel Centre of Experimental Medicine, University Hospital, LMU Munich, Germany
| | - Luisa Fernanda Jiménez-Soto
- Chair of Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, Faculty of Medicine, LMU Munich, Germany
| | - Rainer Haas
- Chair of Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, Faculty of Medicine, LMU Munich, Germany
- German Center for Infection Research (DZIF), LMU Munich, Germany
- * E-mail:
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Rossi I, Spagnoli G, Buttini F, Sonvico F, Stellari F, Cavazzini D, Chen Q, Müller M, Bolchi A, Ottonello S, Bettini R. A respirable HPV-L2 dry-powder vaccine with GLA as amphiphilic lubricant and immune-adjuvant. J Control Release 2021; 340:209-220. [PMID: 34740725 DOI: 10.1016/j.jconrel.2021.11.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 09/16/2021] [Accepted: 11/01/2021] [Indexed: 11/19/2022]
Abstract
Vaccines not requiring cold-chain storage/distribution and suitable for needle-free delivery are urgently needed. Pulmonary administration is one of the most promising non-parenteral routes for vaccine delivery. Through a multi-component excipient and spray-drying approach, we engineered highly respirable dry-powder vaccine particles containing a three-fold repeated peptide epitope derived from human papillomavirus (HPV16) minor capsid protein L2 displayed on Pyrococcus furious thioredoxin as antigen. A key feature of our engineering approach was the use of the amphiphilic endotoxin derivative glucopyranosyl lipid A (GLA) as both a coating agent enhancing particle de-aggregation and respirability as well as a built-in immune-adjuvant. Following an extensive characterization of the in vitro aerodynamic performance, lung deposition was verified in vivo by intratracheal administration in mice of a vaccine powder containing a fluorescently labeled derivative of the antigen. This was followed by a short-term immunization study that highlighted the ability of the GLA-adjuvanted vaccine powder to induce an anti-L2 systemic immune response comparable to (or even better than) that of the subcutaneously administered liquid-form vaccine. Despite the very short-term immunization conditions employed for this preliminary vaccination experiment, the intratracheally administered dry-powder, but not the subcutaneously injected liquid-state, vaccine induced consistent HPV neutralizing responses. Overall, the present data provide proof-of-concept validation of a new formulation design to produce a dry-powder vaccine that may be easily transferred to other antigens.
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Affiliation(s)
- Irene Rossi
- Department of Food and Drug Sciences, University of Parma, Parco Area delle Scienze Parma, Italy; Interdepartmental Center Biopharmanet-tec, University of Parma, Parco Area delle Scienze Parma, Italy
| | - Gloria Spagnoli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze Parma, Italy; Interdepartmental Center Biopharmanet-tec, University of Parma, Parco Area delle Scienze Parma, Italy
| | - Francesca Buttini
- Department of Food and Drug Sciences, University of Parma, Parco Area delle Scienze Parma, Italy; Interdepartmental Center Biopharmanet-tec, University of Parma, Parco Area delle Scienze Parma, Italy
| | - Fabio Sonvico
- Department of Food and Drug Sciences, University of Parma, Parco Area delle Scienze Parma, Italy; Interdepartmental Center Biopharmanet-tec, University of Parma, Parco Area delle Scienze Parma, Italy
| | - Fabio Stellari
- Chiesi Farmaceutici SpA, Largo Belloli 11a, Parma, Italy
| | - Davide Cavazzini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze Parma, Italy
| | - Quigxin Chen
- German Cancer Research Center, Im Neuenheimer Feld 280, Heidelberg, Germany
| | - Martin Müller
- German Cancer Research Center, Im Neuenheimer Feld 280, Heidelberg, Germany
| | - Angelo Bolchi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze Parma, Italy; Interdepartmental Center Biopharmanet-tec, University of Parma, Parco Area delle Scienze Parma, Italy
| | - Simone Ottonello
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze Parma, Italy; Interdepartmental Center Biopharmanet-tec, University of Parma, Parco Area delle Scienze Parma, Italy.
| | - Ruggero Bettini
- Department of Food and Drug Sciences, University of Parma, Parco Area delle Scienze Parma, Italy; Interdepartmental Center Biopharmanet-tec, University of Parma, Parco Area delle Scienze Parma, Italy.
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毛 洪, 何 明, 和 素. [Significance of Lipopolysaccharide Lipid A Gene Mutation of Extensively Drug-resistant Acinetobacter baumanii on Polymyxin Resistance and Its Influence on Treatment]. Sichuan Da Xue Xue Bao Yi Xue Ban 2021; 52:124-128. [PMID: 33474901 PMCID: PMC10408946 DOI: 10.12182/20210160208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To explore the significance of the resistance to polymyxin resistance of the extensively drug resistant Acinetobacter baumannii (XDRAB) lipopolysaccharide (LPS) lpx A, lpx C, lpx D and to screen appropriate combination therapy. METHODS In the past two years, 72 XDRAB in the secretions of our patients were selected as the research object. According to the minimum inhibitory concentration (MIC) of the XDRAB strain on polymyxin, they were included in the drug resistance group and the sensitive group. The gene sequences of strains lpx A, lpx C, lpx D were compared with the standard strains to analyze gene mutations and compared the mutation rates in the drug resistant group and the sensitive group. The efficacy of the combination drugs was evaluated by microcheckerboard dilution method, including polymyxin+imipenem group, polymyxin+meropenem group, polymyxin+cefoperazone/sulbactam group, polymyxin+levofloxacin group, and polymyxin+fosfomycin group. Calculated the fractional inhibitory concentration (FIC) index of the combined medication regimen and compared the percentage of strains that exhibited synergistic, additive, irrelevant, and antagonistic effects. RESULTS Tentyone were in the drug resistant group, accounting for 21 (29.17%,) and 51 were in the sensitive group, accounting for 70.83%. Some strains had mutations in lpx A, lpx C, lpx D genes. The mutation rate in the drug resistant group was 90.48%, which was significantly higher than 11.76% in the sensitive group, the difference was statistically significant ( P<0.05). The combined drug sensitivity test showed, compared with the polymyxin+fosfomycin group, the mycotin+fosfomycin group had a higher percentage of strains with synergistic FIC index in the polymyxin+imipenem group, the difference was statistically significant ( P<0.01). CONCLUSION XDRAB is resistant to polymyxin, which is related to mutations in LPS lipid A biosynthesis genes lpx A, lpx C, lpx D. Clinical treatment should adopt a combination of polymyxin+imipenem/meropenem and other drug combination to reduce the secondary infection of drug resistant bacteria.
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Affiliation(s)
- 洪宾 毛
- 开封市人民医院 临床药学科 (开封 475000)Department of Clinical Pharmacy, Kaifeng People’s Hospital, Kaifeng 475000, China
| | - 明 何
- 开封市人民医院 临床药学科 (开封 475000)Department of Clinical Pharmacy, Kaifeng People’s Hospital, Kaifeng 475000, China
| | - 素娜 和
- 开封市人民医院 临床药学科 (开封 475000)Department of Clinical Pharmacy, Kaifeng People’s Hospital, Kaifeng 475000, China
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Abstract
Many malignant cell surface carbohydrates resulting from abnormal glycosylation patterns of certain diseases can serve as antigens for the development of vaccines against these diseases. However, carbohydrate antigens are usually poorly immunogenic by themselves, thus they need to be covalently coupled with immunologically active carrier molecules to be functional. The most well established and commonly used carriers are proteins. In recent years, the use of toll-like receptor (TLR) ligands to formulate glycoconjugate vaccines has gained significant attention because TLR ligands can serve not only as carrier molecules but also as built-in adjuvants to form fully synthetic and self-adjuvanting conjugate vaccines, which have several advantages over carbohydrate-protein conjugates and formulated mixtures with external adjuvants. This article reviews recent progresses in the development of conjugate vaccines based on TLR ligands. Two major classes of TLR ligands, lipopeptides and lipid A derivatives will be covered with more focus on monophosohoryl lipid A (MPLA) and related analogs, which are TLR4 ligands demonstrated to be able to provoke T cell-dependent, adaptive immune responses. Corresponding conjugate vaccines have shown promising application potentials to multiple diseases including cancer.
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Affiliation(s)
- Qingjiang Li
- Department of Chemistry, University of Florida, 214 Leigh Hall, Gainesville, FL 32611, USA.
| | - Zhongwu Guo
- Department of Chemistry, University of Florida, 214 Leigh Hall, Gainesville, FL 32611, USA.
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Joachim A, Bauer A, Joseph S, Geldmacher C, Munseri PJ, Aboud S, Missanga M, Mann P, Wahren B, Ferrari G, Polonis VR, Robb ML, Weber J, Tatoud R, Maboko L, Hoelscher M, Lyamuya EF, Biberfeld G, Sandström E, Kroidl A, Bakari M, Nilsson C, McCormack S. Boosting with Subtype C CN54rgp140 Protein Adjuvanted with Glucopyranosyl Lipid Adjuvant after Priming with HIV-DNA and HIV-MVA Is Safe and Enhances Immune Responses: A Phase I Trial. PLoS One 2016; 11:e0155702. [PMID: 27192151 PMCID: PMC4871571 DOI: 10.1371/journal.pone.0155702] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 05/02/2016] [Indexed: 12/18/2022] Open
Abstract
Background A vaccine against HIV is widely considered the most effective and sustainable way of reducing new infections. We evaluated the safety and impact of boosting with subtype C CN54rgp140 envelope protein adjuvanted in glucopyranosyl lipid adjuvant (GLA-AF) in Tanzanian volunteers previously given three immunizations with HIV-DNA followed by two immunizations with recombinant modified vaccinia virus Ankara (HIV-MVA). Methods Forty volunteers (35 vaccinees and five placebo recipients) were given two CN54rgp140/GLA-AF immunizations 30–71 weeks after the last HIV-MVA vaccination. These immunizations were delivered intramuscularly four weeks apart. Results The vaccine was safe and well tolerated except for one episode of asymptomatic hypoglycaemia that was classified as severe adverse event. Two weeks after the second HIV-MVA vaccination 34 (97%) of the 35 previously vaccinated developed Env-specific binding antibodies, and 79% and 84% displayed IFN-γ ELISpot responses to Gag and Env, respectively. Binding antibodies to subtype C Env (included in HIV-DNA and protein boost), subtype B Env (included only in HIV-DNA) and CRF01_AE Env (included only in HIV-MVA) were significantly boosted by the CN54rgp140/GLA-AF immunizations. Functional antibodies detected using an infectious molecular clone virus/peripheral blood mononuclear cell neutralization assay, a pseudovirus/TZM-bl neutralization assay or by assays for antibody-dependent cellular cytotoxicity (ADCC) were not significantly boosted. In contrast, T-cell proliferative responses to subtype B MN antigen and IFN-γ ELISpot responses to Env peptides were significantly enhanced. Four volunteers not primed with HIV-DNA and HIV-MVA before the CN54rgp140/GLA-AF immunizations mounted an antibody response, while cell-mediated responses were rare. After the two Env subtype C protein immunizations, a trend towards higher median subtype C Env binding antibody titers was found in vaccinees who had received HIV-DNA and HIV-MVA prior to the two Env protein immunizations as compared to unprimed vaccinees (p = 0.07). Conclusion We report excellent tolerability, enhanced binding antibody responses and Env-specific cell-mediated immune responses but no ADCC antibody increase after two immunizations with a subtype C rgp140 protein adjuvanted in GLA-AF in healthy volunteers previously immunized with HIV-DNA and HIV-MVA. Trial Registration International Clinical Trials Registry PACTR2010050002122368
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Affiliation(s)
- Agricola Joachim
- Department of Microbiology and Immunology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- * E-mail: ;
| | - Asli Bauer
- National Institute for Medical Research-Mbeya, Medical Research Center, Mbeya, Tanzania
- Department of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany
| | - Sarah Joseph
- Medical Research Council Clinical Trials Unit, University College London, London, United Kingdom
| | - Christof Geldmacher
- Department of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany
- German Center for Infection Research (DZIF), partner site Munich, Munich, Germany
| | - Patricia J. Munseri
- Department of Internal Medicine, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Said Aboud
- Department of Microbiology and Immunology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Marco Missanga
- National Institute for Medical Research-Mbeya, Medical Research Center, Mbeya, Tanzania
| | - Philipp Mann
- National Institute for Medical Research-Mbeya, Medical Research Center, Mbeya, Tanzania
| | - Britta Wahren
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Guido Ferrari
- Department of Surgery and Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Victoria R. Polonis
- The Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Merlin L. Robb
- The Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
- The Military HIV Research Program, The Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, United States of America
| | | | | | - Leonard Maboko
- National Institute for Medical Research-Mbeya, Medical Research Center, Mbeya, Tanzania
| | - Michael Hoelscher
- National Institute for Medical Research-Mbeya, Medical Research Center, Mbeya, Tanzania
- Department of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany
- German Center for Infection Research (DZIF), partner site Munich, Munich, Germany
| | - Eligius F. Lyamuya
- Department of Microbiology and Immunology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Gunnel Biberfeld
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Eric Sandström
- Venhälsan, Karolinska Insitutet at Södersjukhuset, Stockholm, Sweden
| | - Arne Kroidl
- National Institute for Medical Research-Mbeya, Medical Research Center, Mbeya, Tanzania
- Department of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany
- German Center for Infection Research (DZIF), partner site Munich, Munich, Germany
| | - Muhammad Bakari
- Department of Internal Medicine, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Charlotta Nilsson
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- The Public Health Agency of Sweden, Solna, Sweden
- Department of Laboratory Medicine, Karolinska Institutet Huddinge, Stockholm, Sweden
| | - Sheena McCormack
- Medical Research Council Clinical Trials Unit, University College London, London, United Kingdom
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Schaub B, Westlake RM, He H, Arestides R, Haley KJ, Campo M, Velasco G, Bellou A, Hawgood S, Poulain FR, Perkins DL, Finn PW. Surfactant protein D deficiency influences allergic immune responses. Clin Exp Allergy 2005; 34:1819-26. [PMID: 15663554 DOI: 10.1111/j.1365-2222.2004.02068.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND The collectin surfactant protein D (SP-D) confers protection against pulmonary infection and inflammation. Recent data suggest a role for SP-D in the modulation of allergic inflammation. OBJECTIVE The aim of this study is to characterize the immune responses of SP-D-deficient (SP-D(-/-)) mice in a kinetic model of allergic inflammation. We determined whether allergic parameters were enhanced in SP-D(-/-) mice in vivo. Further, we examined whether functional immune responses in vitro such as lymphocyte proliferation (LP) and cytokine production were modulated in the absence of SP-D. METHODS In vivo, wild-type (WT) and SP-D(-/-) mice were sensitized and challenged with the allergen ovalbumin (OVA) and assessed for allergic parameters (bronchoalveolar lavage (BAL) eosinophils, IL-13 production, pulmonary IFN-gamma, IL-10 expression) at early time points (1 and 3 days of challenge) in comparison with late time points (7 days of challenge). In vitro, spleen cells from WT and SP-D(-/-) mice were stimulated with the mitogen concanavalin A (ConA) and lipid A (LpA) and analysed for LP, IL-13 and IFN-gamma production. Toll-like receptor 4 (TLR4), ligand for LpA, was assessed by mRNA expression and immunohistochemistry in vivo. RESULTS Following allergen exposure in vivo, SP-D(-/-) mice expressed higher BAL eosinophils and IL-13 concentrations and lower IFN-gamma expression at early time points compared with WT mice. IL-10 expression was increased at early time points in SP-D(-/-) compared with WT mice. Allergen-induced TLR4 expression was increased in WT, but not in SP-D(-/-) mice. After stimulation with LpA and ConA in vitro LP was increased and IFN-gamma concentration was decreased in SP-D(-/-) mice. CONCLUSION SP-D may be critical for the modulation of early stages of allergic inflammation in vivo.
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Affiliation(s)
- B Schaub
- Pulmonary and Critical Care Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA
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Sakai H, Hisamoto S, Fukutomi I, Sou K, Takeoka S, Tsuchida E. Detection of lipopolysaccharide in hemoglobin‐vesicles by Limulus amebocyte lysate test with kinetic–turbidimetric gel clotting analysis and pretreatment of surfactant. J Pharm Sci 2004; 93:310-21. [PMID: 14705189 DOI: 10.1002/jps.10525] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A method to quantitatively measure the bacterial endotoxin content (lipopolysaccharide, LPS) in phospholipid vesicles or liposomes is necessary because the conventional Limulus amebocyte lysate (LAL) test does not provide an accurate measurement due to the hydrophobic interaction of LPS and vesicles that shields the activity of LPS to clot the LAL coagulant. This interference was evident from isothermal titration calorimetry results in our study that clearly demonstrated the insertion of the LPS molecule into the phospholipid bilayer membrane. Hemoglobin-vesicles (HbVs; particle diameter = 251 +/- 80 nm; [Hb] = 10 g/dL) are artificial oxygen carriers encapsulating a conc. Hb solution in phospholipid vesicles, and their oxygen transporting ability has been extensively studied. To accurately measure the LPS content in the HbV suspension, we tested the solubilization of HbV with deca(oxyethylene) dodecyl ether (C(12)E(10)), used to release the LPS entrapped in the vesicles, as a pretreatment for the succeeding LAL assay of the kinetic-turbidimetric gel clotting (detecting wavelength, 660 nm). The C(12)E(10) surfactant interferes with the gel clotting in a concentration-dependent manner, and the optimal condition was determined in terms of minimizing the dilution factor and C(12)E(10) concentration. We clarified the condition that allowed the measurement of LPS at >0.1 endotoxin units (EU)/mL in the HbV suspension. Moreover, the utilization of histidine-immobilized agarose gel effectively concentrated the trace amount of LPS from the C(12)E(10)-solubilized HbV solution and washed out C(12)E(10) as an inhibitory element. The LAL assay with the LPS-adsorbed gel resulted in the detection limit of 0.0025 EU/mL. Pretreatment with C(12)E(10) would be applicable not only to HbVs but also to other drug delivery systems using phospholipid vesicles encapsulating or incorporating functional molecules.
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Affiliation(s)
- Hiromi Sakai
- Advanced Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555, Japan
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Abstract
An enzyme-linked immunosorbent assay (ELISA) utilizing antigen coated on hydrophobic polyvinyldiene fluoride (PVDF) membranes is described for detecting antibodies that bind to squalene (SQE). Because of the prior lack of availability of validated antibodies to SQE, positive controls for the assay were made by immunization with formulations containing SQE to create monoclonal antibodies (mAbs) that reacted with SQE. Among eight immunogens tested, only two induced detectable murine antibodies to SQE: liposomes containing dimyristoyl phosphatidylcholine, dimyristoyl phosphatidylglycerol, 71% SQE, and lipid A [L(71% SQE+LA)], and, to a much lesser extent, an oil-in-water emulsion containing SQE, Tween 80, Span 85, and lipid A. In each case, lipid A served as an adjuvant, but neither SQE alone, SQE mixed with lipid A, liposomes containing 43% SQE and lipid A, nor several other emulsions containing both SQE and lipid A, induced antibodies that reacted with SQE. Monoclonal antibodies produced after immunizing mice with [L(71% SQE+LA)] served as positive controls for developing the ELISA. Monoclonal antibodies were produced that either recognized SQE alone but did not recognize squalane (SQA, the hydrogenated form of SQE), or that recognized both SQE and SQA. As found previously with other liposomal lipid antigens, liposomes containing lipid A also induced antibodies that reacted with the liposomal phospholipids. However, mAbs were also identified that reacted with SQE on PVDF membranes, but did not recognize either SQA or liposomal phospholipid. The polyclonal antiserum produced by immunizing mice with [L(71% SQE+LA)] therefore contained a mixed population of antibody specificities and, as expected, the ELISA of polyclonal antiserum with PVDF membranes detected antibodies both to SQE and SQA. We conclude that SQE is a weak antigen, but that antibodies that specifically bind to SQE can be readily induced by immunization with [L(71% SQE+LA)] and detected by ELISA with PVDF membranes coated with SQE.
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Affiliation(s)
- G R Matyas
- Department of Membrane Biochemistry, Walter Reed Army Institute of Research, Silver Spring, MD 20910-7500, USA.
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36
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Lindskog S, Zetterström O, Kamkar A, Bergman E, Forsgårdh A, Blomlöf L. Skin-prick test for severe marginal periodontitis. INT J PERIODONT REST 1999; 19:373-7. [PMID: 10709504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
The present study tested the hypothesis that treatment-resistant periodontitis patients present with a more intense inflammatory response to marginal bacterial plaque as a sign of an inflammatory overreaction. Patients with severe marginal periodontitis (Gingival Index > 20%) who had not responded to treatment showed almost no positive response to lipid A in a skin-prick test, which was significantly different from the results from patients with severe marginal periodontitis who had responded to treatment and from healthy control individuals without marginal periodontitis. This finding can be interpreted as an impaired inflammatory reactivity to periodontitis pathogens in treatment-resistant patients, rejecting the hypothesis.
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Affiliation(s)
- S Lindskog
- Department of Basic Oral Sciences, School of Dentistry, Karolinska Institute, Stockholm, Sweden.
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37
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38
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Nakazawa T. [Studies on Helicobacter pylori]. Nihon Naika Gakkai Zasshi 1998; 87:801-807. [PMID: 9648428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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39
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Matsukura Y, Takagi T, Okamoto R, Koshino T. Upregulation of CD44 in the inflamed mouse air pouch injected with synthetic lipid A. J Rheumatol 1998; 25:539-45. [PMID: 9517778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To investigate aspects of the inflammatory process of the mouse subcutaneous air pouch -- a facsimile synovial cavity -- induced by injection of lipid A, and to determine the expression and upregulation of CD44 in the lining cell layer of the inflamed air pouch. METHODS Histological changes of inner walls in the mouse air pouch were evaluated 1, 3, and 7 days after injection of lipid A. RESULTS Polymorphonuclear cell infiltration in the lining layer reached the maximum one day after injection of 10 microg of lipid A (10/10 mice in Grade 3; p < 0.01), while mononuclear cell infiltration and lining cell hyperplasia reached the maximum 3 days after injection (5/10 mice in Grade 2; 5/10 in Grade 3; p < 0.05; 39+/-11 layers, p < 0.05, respectively). The number of cell depth of CD44 positive lining layers and interleukin 1alpha (IL-1alpha) positive lining layers reached the maximum 3 days after injection (39+/-7 layers, p < 0.01; 35+/-12 layers, p < 0.05, respectively). CONCLUSION These findings suggest that CD44 may have some connection with the proinflammatory cytokine IL-1alpha and induce inflammatory responses in the air pouch injected with lipid A.
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Affiliation(s)
- Y Matsukura
- Department of Orthopaedic Surgery, School of Medicine, Yokohama City University, Yokohama, Japan
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40
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Abstract
Endotoxin-induced uveitis (EIU) is an animal model of ocular inflammation induced by lipopolysaccharide (LPS). The lipid A (LA) region of the LPS chemical structure is believed to be responsible for virtually all the biological activities induced by LPS. The aim of this study was to perform a more detailed investigation of the potency of LA in reproducing EIU. Various doses of either LPS or LA were injected into the footpad of an inbred strain of Lewis rat and the inflammation patterns were compared by assessing the protein concentration, by cytological study, and by determining the inflammatory cell content in samples of aqueous humor obtained during 96-hour follow-up. Evaluation of the cell number and protein concentration ratio of both groups showed the LA-stimulated group presented a higher ratio than the LPS group (Welch's t-test, (P < 0.00001). It was noteworthy that even the injection of high doses of LPS could not reproduce the level of cellular infiltration induced by LA. Histological study confirmed the enhanced cellularity in the LA group, neutrophils being predominant in both the LPS- and the LA-stimulated groups. The divergent findings in these two models of uveitis may be valuable to further investigations of the process of inflammatory cell migration into the anterior chamber of the eye.
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Affiliation(s)
- R K Hanashiro
- Department of Ophthalmology, University of Tokyo, School of Medicine, Japan
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41
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Chen C, Brock R, Luh F, Chou PJ, Larrick JW, Huang RF, Huang TH. The solution structure of the active domain of CAP18--a lipopolysaccharide binding protein from rabbit leukocytes. FEBS Lett 1995; 370:46-52. [PMID: 7649303 DOI: 10.1016/0014-5793(95)00792-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We have employed the circular dichroism (CD) technique to characterize the solution structure of CAP18(106-137), a lipopolysaccharide (LPS) binding, antimicrobial protein, and its interaction with lipid A. Our results revealed that CAP18(106-137) may exist in at least three lipid A concentration-dependent, primarily helix conformations. The 'model' structure of CAP18(106-137) in 30% (v/v) TFE, determined by nuclear magnetic resonance (NMR) technique, was found to be a complete and very rigid helix. In this conformation, the cationic and hydrophobic groups of CAP18(106-137) are separated into patches and stripes in such a way that it can favorably interact with lipid A through either coulombic interaction with the diphosphoryl groups or hydrophobic interaction with the fatty acyl chains.
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Affiliation(s)
- C Chen
- Division of Structural Biology, Academia Sinica, Nankang, Taipei, Taiwan, ROC
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42
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Tosi PF, Radu D, Nicolau C. Immune response against the murine mdri protein induced by vaccination with synthetic lipopeptides in liposomes. Biochem Biophys Res Commun 1995; 212:494-500. [PMID: 7542878 DOI: 10.1006/bbrc.1995.1997] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Intrinsically, or after exposure to chemotherapeutic drugs, many cancer cells overexpress a class of high molecular weight membrane glycoproteins associated with the multidrug resistance (mdr) of these cells. This report describes an immunization protocol eliciting autoantibodies specific to extracellular epitopes of the murine mdr 1 P-glycoprotein (Pgp). Synthetic peptides with the sequences of extracellular loops of murine Pgp were covalently coupled with four palmitic acid moieties per peptide molecule. These "lipopeptides" were reconstituted in the bilayer of liposomes containing lipid A and used to immunize mice. Antibodies against the lipopeptides corresponding to loop 2 and 4 were elicited in sera of immunized mice. They reacted specifically with extracellular epitopes of the naturally occurring murine Pgp. After interaction with resistant cancer cells, the antibodies induced an average 50% increase in cellular accumulation of doxorubicin and Bodipy-verapamil. In the presence of these antibodies the resistance of L1210 mdr cells was reduced from an LD50 of 4 x 10(-5) M to 5 x 10(-7) M doxorubicin.
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Affiliation(s)
- P F Tosi
- Center for Blood Research Laboratories, Boston, MA 02135, USA
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43
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Pleşca LA, Bodizs G, Cucuianu M, Colhon D. Hemostatic balance during the acute inflammatory reaction; with special reference to antithrombin III. Rom J Physiol 1995; 32:71-6. [PMID: 8896078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Inflammatory reaction caused by intramuscular injections of turpentine in 5 rabbits led to an obvious increase of not only plasma fibrinogen and factor VIII: C levels, but also of plasma antithrombin III activity, measured by a chromogenic assay as heparin cofactor. This activity rose from 80% +/- 10,8 (mean +/- SEM) before the injection to 123% +/- 6,56 48 hours later. Changes affecting plasma fibrinogen level and antithrombin II activity were much lesser in a group of 5 rabbits given small doses of intravenous endotoxin. It is considered that acute inflammation is accompanied by the setting of the hemostatic balance at a higher level.
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Affiliation(s)
- L A Pleşca
- Department of Physiopathology, University of Medicine and Pharmachy Cluj
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44
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45
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Yokota S. [Structure and function of Pseudomonas aeruginosa lipopolysaccharide (endotoxin)]. Nihon Rinsho 1991; 49:2233-8. [PMID: 1721096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- S Yokota
- Biotechnology Laboratory, Takarazuka Research Center, Sumitomo Chemical Co., Ltd
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46
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Brandenburg K, Seydel U. Investigation into the fluidity of lipopolysaccharide and free lipid A membrane systems by Fourier-transform infrared spectroscopy and differential scanning calorimetry. Eur J Biochem 1990; 191:229-36. [PMID: 2199198 DOI: 10.1111/j.1432-1033.1990.tb19114.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The phase behaviour, particularly the fluidity within each phase state and the transitions between them, of lipopolysaccharides and of their lipid moiety, free lipid A, of various species of Gram-negative bacteria, especially of Salmonella minnesota and Escherichia coli, has been investigated by applying mainly Fourier-transform infrared spectroscopy and differential scanning calorimetry. For enterobacterial strains, the transition temperatures of the gel----liquid crystalline (beta----alpha) phase transition of the hydrocarbon chains in dependence on the length of the sugar moiety are highest for free lipids A (around 45 degrees C) and lowest for deep rough mutant lipopolysaccharides (around 30 degrees C). Evaluating certain infrared active vibration bands of the hydrocarbon moiety, mainly the symmetric stretching vibration of the methylene groups around 2850 cm-1, it was found that, in the gel state, the acyl chains of lipopolysaccharides and free lipid A have a higher fluidity as compared with saturated and the same fluidity as compared with unsaturated phospholipids. This 'partial fluidization' of lipopolysaccharide below the transition temperature correlates with its reduced enthalpy change at that temperature compared to phospholipids with the same chain length. The fluidity depends strongly on ambient conditions, i.e. on the Mg2+ and H+ content: higher Mg2+ concentrations and low pH values make the acyl chains of free lipid A and lipopolysaccharide preparations significantly more rigid and also partially increase the transition temperature. The influence of Mg2+ is highest for free lipid A and decreases with increasing length of the sugar side chain within the lipopolysaccharide molecules, whereas the effect of a low pH is similar for all preparations. At basic pH, a fluidization of the lipopolysaccharide and lipid A acyl chains and a decrease in transition temperature take place. Free lipid A and all investigated rough mutant lipopolysaccharides exhibit an extremely strong lyotropic behaviour in the beta----alpha melting enthalpy but not in the value of the transition temperature. The phase transition is distinctly expressed only at water concentrations higher than 50-60%. A further increase of the water content still leads to an increase in the phase-transition enthalpy, particularly for lipopolysaccharides with a more complete sugar moiety. The fluidity of the hydrocarbon chains is shown to be an important parameter with respect to the expression of biological activities.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- K Brandenburg
- Forschungsinstitut Borstel, Institut für Experimentelle Biologie und Medizin, Federal Republic of Germany
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47
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Abstract
After covalent attachment of bacterial lipopolysaccharide to the nucleoprotein of influenza A virus, this water-soluble antigen could be incorporated firmly into ISCOM. This potent "immunostimulating complex" induced the production of high antibody titers in mice and could partially protect the animals from a lethal challenge infection. After immunization with ISCOM preparations NP-specific cytotoxic T cell activity could not be demonstrated.
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Affiliation(s)
- H P Weiss
- Institut für Virologie, Justus-Liebig-Universität Giessen, Federal Republic of Germany
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48
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49
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Seydel U, Brandenburg K, Koch MH, Rietschel ET. Supramolecular structure of lipopolysaccharide and free lipid A under physiological conditions as determined by synchrotron small-angle X-ray diffraction. Eur J Biochem 1989; 186:325-32. [PMID: 2689173 DOI: 10.1111/j.1432-1033.1989.tb15212.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Lipopolysaccharides, the major amphiphilic components of the outer leaflet of the outer membrane of Gram-negative bacteria, may assume various three-dimensional supramolecular structures depending on molecular properties (e.g. chemical structure) and on ambient conditions (e.g. temperature, concentration of divalent cations). We applied synchrotron small-angle X-ray diffraction to investigate the supramolecular structures of natural and synthetic Escherichia-coli-type lipid A, of lipid A from Salmonella minnesota, and of rough mutant lipopolysaccharides of E. coli and S. minnesota under physiological water content (greater than 90%) at different temperatures (20, 37, and 55 degrees C) and at different lipid/divalent cation molar ratios (20:1 to 1:1). We found that in the absence of divalent cations rough mutant lipopolysaccharide and free lipid A form unilamellar structures with the main reflections centered around 4.50 nm for free lipid A, 4.80 nm for Re lipopolysaccharide, and 5.90 nm for Rd1 lipopolysaccharide at 20 degrees C, i.e. below the beta----alpha acyl-chain-melting transition temperature. Above this temperature, the reflections are shifted to 4.30 nm for free lipid A (at 55 degrees C), 4.60 nm for Re lipopolysaccharide (at 37 degrees C), and to 5.50 nm for Rd1 lipopolysaccharide (at 37 degrees C). The addition of divalent cations leads (at lower concentrations, i.e. lipid/cation molar ratios 20:1 to 5:1) to sharper reflections expressing a higher state of order and to a shift of the center of the main reflections lying now at 5.10 nm for free lipid A, 6.40 nm for Re and 7.20 nm for Rd1 lipopolysaccharide at 20 degrees C. At higher concentrations of divalent cations (e.g. lipid/cation molar ratio 1:1), an increasing tendency to form nonlamellar, inverted cubic structures is observed which is indicated by the occurrence of another main periodicity and/or of reflections with spacing ratios 1: square root of 2, 1: square root of 3 of the main periodicity. The tendency to assume inverted cubic structures is only weakly pronounced for rough mutant lipopolysaccharides but dominant for free lipid A even at physiological temperature and divalent cation concentration.
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Affiliation(s)
- U Seydel
- Forschungsinstitut Borstel, Institut für Experimentelle Biologie und Medizin, FRG
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50
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Magnuson DK, Weintraub A, Pohlman TH, Maier RV. Human endothelial cell adhesiveness for neutrophils, induced by Escherichia coli lipopolysaccharide in vitro, is inhibited by Bacteroides fragilis lipopolysaccharide. J Immunol 1989; 143:3025-30. [PMID: 2681420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Recent studies in vitro have demonstrated that LPS from Gram-negative bacteria are capable of inducing endothelial cells to express a cell surface property that promotes the adherence of neutrophils (polymorphonuclear cells, PMN). We have investigated the effects of LPS from Bacteroides fragilis, an organism documented to have little toxicity in vivo, on the induction of this property in human endothelial cells. Monolayers of cultured human umbilical vein endothelial cells (HUVE) exhibited no increase in adhesiveness for 51Cr-radiolabeled PMN after 4 h of exposure to B. fragilis LPS from 1 ng to 10 micrograms/ml. Escherichia coli LPS elicited a dose-dependent enhancement of HUVE adhesiveness for PMN over the same concentration range, reaching a maximum of 49.4 +/- 6.6% at 10 micrograms/ml. Like E. coli LPS, B. fragilis LPS converted chromogenic substrate in the Limulus amebocyte lysate assay, and was directly cytotoxic to bovine aortic endothelial cells. Both B. fragilis LPS activities required doses two-to-three log-fold higher than for E. coli LPS. In addition, we found that B. fragilis LPS inhibited the induction of HUVE adhesiveness for PMN by E. coli LPS. This inhibition was also dose-dependent, becoming maximal (greater than 80%) when B. fragilis LPS was in 10- to 20-fold excess. Tumor necrosis factor and IL-1, two monokines which also elicit HUVE adhesiveness for PMN, were not inhibited by B. fragilis LPS, suggesting a mechanism of HUVE activation by LPS which is signal-specific, and which recognizes specificities of LPS structure.
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Affiliation(s)
- D K Magnuson
- Department of Surgery, University of Washington, Seattle 98195
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