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Structure type: polymer chemical repeating unit
Compound class: O-polysaccharide, O-antigen, CPS
Contained glycoepitopes: IEDB_151083,IEDB_221847,IEDB_221848

• Article ID: 514
  Vinogradov E, Conlan WJ, Gunn JS, Perry MB "Characterization of the lipopolysaccharide O-antigen of Francisella novicida (U112)" - Carbohydrate Research 339(3) (2004) 649-654
  

  Francisella novicida (U112), a close relative of the highly virulent bacterium F. tularensis, was shown to produce a lipopolysaccharide in which the antigenic O-polysaccharide component was found by chemical, (1)H and (13)C NMR and MS analyses to be an unbranched neutral linear polymer of a repeating tetrasaccharide unit composed of 2-acetamido-2-deoxy-d-galacturonamide (d-GalNAcAN) and 2,4-diacetamido-2,4,6-trideoxy-d-glucose (d-Qui2NAc4NAc, di-N-acetylbacillosamine) residues (3:1) and had the structure: [Formula: see text] With polyclonal murine antibody, the F. novicida O-antigen did not show serological cross-reactivity with the O-antigen of F. tularensis despite the occurrence of a common →4)-d-GalpNAcAN-(1→4)-α-D-GalpNAcAN-(1→ disaccharide unit in their respective O-antigens. Thus, O-PS serology offers a practical way to distinguish between the two Francisella species.

  Lipopolysaccharide, NMR, structure, common, tetrasaccharide, characterization, O-antigen, antigenic, O antigen, polymer, Research, antibodies, antibody, O-polysaccharide, O antigens, O polysaccharide, O-antigens, bacteria, neutral, serological, serology, biological, chemical, component, MS, disaccharide, linear, occurrence, lipopolysaccharide O-antigen, species, cross-reactivity, crossreactivity, virulent, PDF, murine

  NCBI PubMed ID: 15013402
  Journal NLM ID: 0043535
  Publisher: Elsevier
  Correspondence: malcolm.perry@nrc-cnrc.gc.ca
  Institutions: Institute for Biological Sciences, National Research Council, Ottawa, Ontario, Canada K1A OR6, Department of Virology, Immunology and Medical Genetics, Department of Medicine, Division of Infectious Diseases, The Center for Microbial Interface Biology, The Ohio State University, Columbus, OH, USA
  Methods: NMR-2D, methylation, NMR, sugar analysis, MS
  
   
  
  Francisella tularensis
  CSDB ID 9363 (all data & tools)
• Article ID: 776
  Conlan JW, Vinogradov E, Monteiro MA, Perry MB "Mice intradermally-inoculated with the intact lipopolysaccharide, but not the lipid A or O-chain, from Francisella tularensis LVS rapidly acquire varying degrees of enhanced resistance against systemic or aerogenic challenge with virulent strains of the pathogen" - Microbial Pathogenesis 34(1) (2003) 39-45
  

  The present study examines the relationship between the structure and important biological effects of the lipopolysaccharide (LPS) of the intracellular bacterial pathogen, Francisella tularensis LVS. It shows that treating mice with sub-immunogenic amounts of intact F. tularensis LPS rapidly induces an enhanced resistance to intradermal or aerogenic challenge with strains of the pathogen of varying virulence. However, neither the free Lipid A nor core-O-chain produced by mild acid hydrolysis of LPS appeared able to elicit this host defense mechanism

  Lipopolysaccharide, LPS, structure, Bacterial, host, strain, virulence, Research, degree, acid, lipid, lipid A, enhanced, mice, hydrolysis, biological, mechanism, intracellular, O-chain, pathogen, Francisella tularensis, relationship, resistance, effect, virulent, challenge, defense, free, host defense

  NCBI PubMed ID: 12620383
  Journal NLM ID: 8606191
  Publisher: Academic Press
  Institutions: National Research Council Canada, Institute for Biological Sciences, 100 Sussex Drive, Room 3065, K1A OR6, Ottawa, Ont., Canada
  Methods: NMR-2D, NMR
  
   
  
  Francisella tularensis LVS
  CSDB ID 1244 (all data & tools)
• Article ID: 1120
  Prior JL, Prior RG, Hitchen PG, Diaper H, Griffin KF, Morris HR, Dell A, Titball RW "Characterization of the O antigen gene cluster and structural analysis of the O antigen of Francisella tularensis subsp. tularensis" - Journal of Medical Microbiology (2003) 845-851
  

  A gene cluster encoding enzymes involved in LPS O antigen biosynthesis was identified from the partial genome sequence of Francisella tularensis subsp. tularensis Schu S4. All of the genes within the cluster were assigned putative functions based on sequence similarity with genes from O antigen biosynthetic clusters from other bacteria. Ten pairs of overlapping primers were designed to amplify the O antigen biosynthetic cluster by PCR from nine strains of F. tularensis. Although the gene cluster was present in all strains, there was a size difference in one of the PCR products between subsp. tularensis strains and subsp. holarctica strains. LPS was purified from F. tularensis subsp. tularensis Schu S4 and the O antigen was shown by mass spectrometry to have a structure similar to that of F. tularensis subsp. holarctica strain 15. When LPS from F. tularensis subsp. tularensis Schu S4 was used to immunize mice that were then challenged with F. tularensis subsp. tularensis Schu S4, an extended time to death was observed

  biosynthesis, antigen, LPS, structure, biosynthetic, gene, PCR, strain, structural, characterization, O-antigen, analysis, structural analysis, O antigen, mice, cluster, gene cluster, bacteria, spectrometry, putative, mass spectrometry, sequence, enzyme, function, difference, purified, Francisella tularensis, time, Enzymes, similarity, genome, size, death

  NCBI PubMed ID: 12972577
  Journal NLM ID: 0224131
  Publisher: Reading, England: Society for General Microbiology
  Correspondence: JLPRIOR@dstl.gov.uk
  Institutions: Dstl Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
  
   
  
  Francisella tularensis ssp. tularensis
  CSDB ID 4085 (all data & tools)
• Article ID: 1569
  Thirumalapura NR, Goad DW, Mort A, Morton RJ, Clarke J, Malayer J "Structural analysis of the O-antigen of Francisella tularensis subspecies tularensis strain OSU 10" - Journal of Medical Microbiology (2005) 693-695
  

  no abstract

  O-antigen, structural analysis, Francisella tularensis

  NCBI PubMed ID: 15947437
  Journal NLM ID: 0224131
  Publisher: Reading, England: Society for General Microbiology
  Correspondence: malayer@okstate.edu
  Institutions: Departments of Physiological Sciences, Biochemistry and Molecular Biology and Veterinary Pathobiology, Oklahoma State University, 264 McElroy Hall, Stillwater, OK 74078, USA, Nomadics Inc., 1024 S Innovation Way, Stillwater, OK 74074, USA
  Methods: NMR, composition analysis
  
   
  
  Francisella tularensis ssp. tularensis OSU10
  CSDB ID 10167 (all data & tools)
• Article ID: 1777
  Knirel YA, Kochetkov NK "The structure of lipopolysaccharides of gram-negative bacteria. III. The structure of O-antigens: A review" - Biochemistry (Moscow) 59(12) (1994) 1325-1383
  

  This review summarizes data on the composition and structure of the O-antigens, the polysaccharide chains of the outer-membrane lipopolysaccharides (LPS) of Gram-negative bacteria defining the immunospecificity of these microbial cells. Special reference is given to some structural features of the O-antigens, such as the presence of unique monosaccharides and noncarbohydrate components, masked regularity, and the occurrence in one microorganism of LPS with structurally different polysaccharide chains. Antigenic relationships between microorganisms belonging to different taxonomic groups are discussed.

  structure, O-antigen, chemical composition, bacterial lipopolysaccharides, Salmonella livingstone C1

  NCBI PubMed ID: 7533007
  Journal NLM ID: 0376536
  Publisher: Nauka/Interperiodica
  Institutions: Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
  
   
  
  Francisella tularensis 15
  CSDB ID 108578 (all data & tools)
• Article ID: 2192
  Vinogradov EV, Shashkov AS, Knirel YA, Kochetkov NK, Tochtamysheva NV, Averin SF, Goncharova OV, Khlebnikov VS "Structure of the O-antigen of Francisella tularensis strain 15" - Carbohydrate Research 214 (1991) 289-297
  

  The O-specific polysaccharide, obtained by mild acid degradation of the lipopolysaccharide of Francisella tularensis strain 15, contained 2-acetamido-2,6-dideoxy-D-glucose (D-QuiNAc), 4,6-dideoxy-4-formamido-D-glucose (D-Qui4NFm), and 2-acetamido-2-deoxy-D-galacturonamide (D-GalNAcAN) in the ratios 1:1:2. Tri- and tetra-saccharide fragments were obtained on treatment of the polysaccharide with anhydrous hydrogen fluoride and partial hydrolysis with 0.1 M hydrochloric acid, respectively. On the basis of 1H- and 13C-n.m.r. spectroscopy of the polysaccharide and the saccharides, it was concluded that the O-antigen had the structure: →4)-α-D-GalpNAcAN-(1→4)-α-D-GalpNAcAN-(1→3)-β-D-QuipNAc-(1→2)-β-D-Quip4NFm-(1→. This O-antigen is related in structure to those of Pseudomonas aeruginosa O6, immunotype 1, and IID 1008, and Shigella dysenteriae type 7.

  NCBI PubMed ID: 1769021
  Publication DOI: 10.1016/0008-6215(91)80036-m
  Journal NLM ID: 0043535
  Publisher: Elsevier
  Institutions: N. D. Zelinsky Institute of Organic Chemistry, Academy of Sciences of the U.S.S.R., Moscow
  Methods: 13C NMR, 1H NMR, partial acid hydrolysis, HF solvolysis, sugar analysis, GLC, deamination, GPC, NaBH4 reduction
  
   
  
  Francisella tularensis bv. palaearctica, Francisella tularensis B, Francisella tularensis 15
  CSDB ID 116261 (all data & tools)
• Article ID: 3813
  Apicella MA, Post DM, Fowler AC, Jones BD, Rasmussen JA, Hunt JR, Imagawa S, Choudhury B, Inzana TJ, Maier TM, Frank DW, Zahrt TC, Chaloner K, Jennings MP, McLendon MK, Gibson BW "Identification, characterization and immunogenicity of an O-antigen capsular polysaccharide of Francisella tularensis" - PLoS One 5(7) (2010) e11060
  

  Capsular polysaccharides are important factors in bacterial pathogenesis and have been the target of a number of successful vaccines. Francisella tularensis has been considered to express a capsular antigen but none has been isolated or characterized. We have developed a monoclonal antibody, 11B7, which recognizes the capsular polysaccharide of F. tularensis migrating on Western blot as a diffuse band between 100 kDa and 250 kDa. The capsule stains poorly on SDS-PAGE with silver stain but can be visualized using ProQ Emerald glycoprotein stain. The capsule appears to be highly conserved among strains of F. tularensis as antibody 11B7 bound to the capsule of 14 of 14 F. tularensis type A and B strains on Western blot. The capsular material can be isolated essentially free of LPS, is phenol and proteinase K resistant, ethanol precipitable and does not dissociate in sodium dodecyl sulfate. Immunoelectron microscopy with colloidal gold demonstrates 11B7 circumferentially staining the surface of F. tularensis which is typical of a polysaccharide capsule. Mass spectrometry, compositional analysis and NMR indicate that the capsule is composed of a polymer of the tetrasaccharide repeat, 4)-α-D-GalNAcAN-(1→4)-α-D-GalNAcAN-(1→3)-β-D-QuiNAc-(1→2)-β-D-Qui4NFm-(1-, which is identical to the previously described F. tularensis O-antigen subunit. This indicates that the F. tularensis capsule can be classified as an O-antigen capsular polysaccharide. Our studies indicate that F. tularensis O-antigen glycosyltransferase mutants do not make a capsule. An F. tularensis acyltransferase and an O-antigen polymerase mutant had no evidence of an O-antigen but expressed a capsular antigen. Passive immunization of BALB/c mice with 75 microg of 11B7 protected against a 150 fold lethal challenge of F. tularensis LVS. Active immunization of BALB/c mice with 10 microg of capsule showed a similar level of protection. These studies demonstrate that F. tularensis produces an O-antigen capsule that may be the basis of a future vaccine.

  Pathogenesis, O-antigen, capsular polysaccharide, Francisella tularensis, immunogenicity

  NCBI PubMed ID: 20625403
  Publication DOI: 10.1371/journal.pone.0011060
  Journal NLM ID: 101285081
  Publisher: San Francisco, CA: Public Library of Science
  Correspondence: michael-apicella@uiowa.edu
  Institutions: Department of Microbiology, University of Iowa, Iowa City, Iowa, United States of America
  Methods: 13C NMR, 1H NMR, GC-MS, ELISA, MALDI-MS, Western blotting, MALDI-TOF MS, biological assays, composition analysis, serological methods, electron microscopy, HF treatment
  
   
  
  Francisella tularensis, Francisella tularensis ssp. tularensis SCHU S4, Francisella tularensis ssp. holartica
  CSDB ID 25176 (all data & tools)
• Article ID: 3902
  Mokrievich AN, Kondakova AN, Valade E, Platonov ME, Vakhrameeva GM, Shaikhutdinova RZ, Mironova RI, Blaha D, Bakhteeva IV, Titareva GM, Kravchenko TB, Kombarova TI, Vidal D, Pavlov VM, Lindner B, Dyatlov IA, Knirel YA "Biological properties and structure of the lipopolysaccharide of a vaccine strain of Francisella tularensis generated by inactivation of a quorum sensing system gene qseC" - Biochemistry (Moscow) 75(4) (2010) 443-451
  

  A knockout mutant with a deletion in a quorum sensing system gene qseC was generated from the vaccine strain Francisella tularensis 15 by site-directed mutagenesis. The variant with the inactivated gene qseC differed from the parental strain in growth rate on solid nutrient medium but had the same growth dynamics in liquid nutrient medium. The mutation abolished almost completely the resistance of the vaccine strain to normal rabbit serum and its ability to survive in macrophages; in addition, the strain lost the residual virulence. A significant phenotypic alteration was observed in the lipopolysaccharide of F. tularensis. Particularly, the mutant strain synthesized no noticeable amount of the lipopolysaccharide with the high-molecular-mass O-polysaccharide, presumably as a result of impairing biosynthesis of the repeating unit, namely, a loss of the ability to incorporate a formyl group, an N-acyl substituent of 4-amino-4,6-dideoxy-D-glucose.

  Lipopolysaccharide, Francisella tularensis, tularemia, quorum sensing, gene qseC, site
  directed mutagenesis

  NCBI PubMed ID: 20618133
  Journal NLM ID: 0376536
  Publisher: Nauka/Interperiodica
  Correspondence: mokrievich@obolensk.org
  Institutions: State Research Center for Applied Microbiology and Biotechnology, Obolensk, Moscow Region, 142279, Russia
  Methods: SDS-PAGE, DNA techniques, mild acid hydrolysis, ESI-FTICR-MS, Western blotting, genetic methods
  
   
  
  Francisella tularensis 15
  CSDB ID 25351 (all data & tools)
• Article ID: 4055
  Kondakova AN, Kirsheva NA, Shashkov AS, Shaikhutdinova RZ, Arbatsky NP, Ivanov SA, Anisimov AP, Knirel YA "Low structural diversity of the O-polysaccharides of Photorhabdus asymbiotica subspp. asymbiotica and australis and their similarity to the O-polysaccharides of taxonomically remote bacteria including Francisella tularensis" - Carbohydrate Research 346(13) (2011) 1951-1955
  

  The O-polysaccharides were isolated from the lipopolysaccharides of emerging human pathogens Photorhabdus asymbiotica subsp. asymbiotica US-86 and US-87 and subsp. australis AU36, AU46, and AU92. Studies by sugar analysis and (1)H and (13)C NMR spectroscopy before and after O-deacetylation showed that the O-polysaccharide structures are essentially identical within, and only slightly different between, the subspecies. The following structures of the repeating units of the O-polysaccharides were established: →3)-β-d-Quip4NGlyFo-(1→4)-α-d-GalpNAcAN3Ac-(1→4)-α-d-GalpNAcA3R-(1→3)-α-d-QuipNAc-(1→ where GalNAcA stands for 2-acetamido-2-deoxygalacturonic acid, GalNAcAN for amide of GalNAcA, QuiNAc for 2-acetamido-2,6-dideoxyglucose, and Qui4NGlyFo for 4,6-dideoxy-4-(N-formylglycyl)aminoglucose; R=Ac in subsp. asymbiotica or H in subsp. australis. The structures established resemble those of a number of taxonomically remote bacteria including Francisella tularensis (Vinogradov, E. V.; Shashkov, A. S.; Knirel, Y. A.; Kochetkov, N. K.; Tochtamysheva, N. V.; Averin, S. P.; Goncharova, O. V.; Khlebnikov, V. S. Carbohydr. Res.1991, 214, 289-297), which differs in (i) the presence of a formyl group on Qui4N rather than the N-formylglycyl group, (ii) the mode of the linkage between the repeating units (β1→2 vs α1→3), (iii) amidation of both GalNAcA residues rather than one residue, and iv) the lack of O-acetylation.

  Lipopolysaccharide, O-antigen, bacterial polysaccharide structure, glycine, formyl, Photorhabdus asymbiotica

  NCBI PubMed ID: 21816392
  Journal NLM ID: 0043535
  Publisher: Elsevier
  Correspondence: A.N. Kondakova
  Institutions: N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
  Methods: 13C NMR, 1H NMR, NMR-2D, sugar analysis, GLC, mild acid hydrolysis, de-O-acetylation
  
   
  
  Francisella tularensis 15
  CSDB ID 26854 (all data & tools)
• Article ID: 4111
  Shilova NV, Navakouski MJ, Huflejt M, Kuehn A, Grunow R, Blixt O, Bovin NV "Changes in the repertoire of natural antibodies caused by immunization with bacterial antigens" - Biochemistry (Moscow) 76(7) (2011) 862-866
  

  The repertoire of natural anti-glycan antibodies in naive chickens and in chickens immunized with bacteria Burkholderia mallei, Burkholderia pseudomallei, and Francisella tularensis as well as with peptides from an outer membrane protein of B. pseudomallei was studied. A relatively restricted pattern of natural antibodies (first of all IgY against bacterial cell wall peptidoglycan fragments, L-Rha, and core N-acetyllactosamine) shrank and, moreover, the level of detectable antibodies decreased as a result of immunization.

  Burkholderia pseudomallei, Francisella tularensis, bacterial polysaccharides, Burkholderia mallei, natural antibodies

  NCBI PubMed ID: 21999548
  Publication DOI: 10.1134/S0006297911070170
  Journal NLM ID: 0376536
  Publisher: Nauka/Interperiodica
  Correspondence: bovin@carbohydrate.ru
  Institutions: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. MiklukhoMaklaya 16/10, 117997 Moscow, Russia
  Methods: serological methods, immunization
  
   
  
  Francisella tularensis
  CSDB ID 26472 (all data & tools)
• Article ID: 4328
  Knirel YA "Structure of O-antigens" - Book: Bacterial lipopolysaccharides: Structure, chemical synthesis, biogenesis and interaction with host cells (2011) Chapter 3, 41-115
  

  The lipopolysaccharide (LPS) is the major constituent of the outer leaflet of the outer membrane of Gram-negative bacteria. Its lipid A moiety is embedded in the membrane and serves as an anchor for the rest of the LPS molecule. The outermost repetitive glycan region of the LPS is linked to the lipid A through a core oligosaccharide (OS), and is designated as the O-specific polysaccharide (O-polysaccharide, OPS) or O-antigen. The O-antigen is the most variable portion of the LPS and provides serological specificity, which is used for bacterial serotyping. The OPS also provides protection to the microorganisms from host defenses such as complement mediated killing and phagocytosis, and is involved in interactions of bacteria with plants and bacteriophages. Studies of the OPSs ranging from the elucidation of their chemical structures and conformations to their biological and physico-chemical properties help improving classification schemes of Gram-negative bacteria. Furthermore, these studies contributed to a better understanding of the mechanisms of pathogenesis of infectious diseases, as well as provided information to develop novel vaccines and diagnostic reagents.

  Lipopolysaccharide, synthesis, lipopolysaccharides, structure, Bacterial, host, O-antigen, O antigen, cell, O antigens, O-antigens, chemical, interaction, cells, PDF, chemical synthesis, biogenesis

  Publication DOI: 10.1007/978-3-7091-0733-1_3
  Publisher: Springer
  Correspondence: knirel@ioc.ac.ru
  Editors: Knirel YA, Valvano MA
  Institutions: Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
  
   
  
  Francisella tularensis ssp. tularensis, Francisella tularensis ssp. holarctica type A, Francisella tularensis ssp. holarctica type B
  CSDB ID 27824 (all data & tools)
• Article ID: 4380
  Rynkiewicz MJ, Lu Z, Hui JH, Sharon J, Seaton BA "Structural Analysis of a Protective Epitope of the Francisella tularensis O-Polysaccharide" - Biochemistry 51(28) (2012) 5684-2694
  

  Francisella tularensis (Ft), the Gram-negative facultative intracellular bacterium that causes tularemia, is considered a biothreat because of its high infectivity and the high mortality rate of respiratory disease. The Ft lipopolysaccharide (Ft LPS) is thought to be a main protective antigen in mice and humans, and we have previously demonstrated the protective effect of the Ft LPS-specific monoclonal antibody Ab52 in a mouse model of respiratory tularemia. Immunochemical characterization has shown that the epitope recognized by Ab52 is contained within two internal repeat units of the O-polysaccharide [O-antigen (OAg)] of Ft LPS. To further localize the Ab52 epitope and understand the molecular interactions between the antibody and the saccharide, we determined the X-ray crystal structure of the Fab fragment of Ab52 and derived an antibody-antigen complex using molecular docking. The docked complex, refined through energy minimization, reveals an antigen binding site in the shape of a large canyon with a central pocket that accommodates a V-shaped epitope consisting of six sugar residues, α-D-GalpNAcAN(1→4)-α-D-GalpNAcAN(1→3)-β-D-QuipNAc(1→2)-β-D-Quip4NFm(1→4)-α-D-GalpNAcAN(1→4)-α-D-GalpNAcAN. These results inform the development of vaccines and immunotherapeutic/immunoprophylactic antibodies against Ft by suggesting a desired topology for binding of the antibody to internal epitopes of Ft LPS. This is the first report of an X-ray crystal structure of a monoclonal antibody that targets a protective Ft B cell epitope.

  Lipopolysaccharide, antigen, O-antigen, X-ray, epitope, monoclonal antibodies, Francisella tularensis, binding site, tularemia, immunochemical characterization

  NCBI PubMed ID: 22747335
  Publication DOI: 10.1021/bi201711m
  Journal NLM ID: 0370623
  Publisher: American Chemical Society
  Correspondence: seatonba@bu.edu
  Institutions: Department of Physiology and Biophysics and double daggerDepartment of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts 02118, United States
  Methods: X-ray, DNA techniques, RT-PCR
  
   
  
  Francisella tularensis
  CSDB ID 27300 (all data & tools)
• Article ID: 4567
  Lu Z, Rynkiewicz MJ, Yang CY, Madico G, Perkins HM, Wang Q, Costello CE, Zaia J, Seaton BA, Sharon J "The binding sites of monoclonal antibodies to the nonreducing end of Francisella tularensis O-antigen accommodate mainly the terminal saccharide" - Immunology 140(3) (2013) 374-389
  

  We have previously described two types of protective B cell epitopes in the O-antigen (OAg) of the Gram negative bacterium Francisella tularensis: repeating internal epitopes targeted by the vast majority of anti-OAg monoclonal antibodies (mAbs), and a non-overlapping epitope at the nonreducing end targeted by the previously unique IgG2a mAb FB11. We now generated and characterized three mAbs specific for the nonreducing end of F. tularensis OAg, partially encoded by the same variable region germline genes, indicating that they target the same epitope. Like FB11, the new mAbs, Ab63 (IgG3), N213 (IgG3), and N62 (IgG2b), had higher antigen-binding bivalent avidity than internal-binding anti-OAg mAbs, and an oligosaccharide containing a single OAg repeat was sufficient for optimal inhibition of their antigen-binding. The X-ray crystal structure of N62 Fab showed that the antigen-binding site is lined mainly by aromatic amino acids that form a small cavity, which can accommodate no more than one and a third sugar residues, indicating that N62 binds mainly to the terminal Qui4NFm residue at the nonreducing end of OAg. In efficacy studies with mice infected intranasally with the highly virulent F. tularensis strain SchuS4, N62, N213 and Ab63 prolonged survival and reduced blood bacterial burden. These results yield insights into how antibodies to nonreducing ends of microbial polysaccharides can contribute to immune protection despite the smaller size of their target epitopes compared with antibodies to internal polysaccharide regions.

  epitopes, vaccines, immunoglobulins, bacteria/bacterial immunity, endotoxin/lipopolysaccharide

  NCBI PubMed ID: 23844703
  Publication DOI: 10.1111/imm.12150
  Journal NLM ID: 0374672
  Publisher: Oxford, UK: Blackwell Scientific Publications
  Correspondence: jsharon@bu.edu
  Institutions: Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, USA
  Methods: X-ray, ELISA, Western blotting, biological assays, serological methods
  
   
  
  Francisella tularensis
  CSDB ID 29262 (all data & tools)
• Article ID: 4585
  Okan NA, Kasper DL "The atypical lipopolysaccharide of Francisella" - Carbohydrate Research 378 (2013) 79-83
  

  Bacterial lipopolysaccharides (LPSs) are ubiquitous molecules that are prominent components of the outer membranes of most gram-negative bacteria. Genetic and structural characterizations of Francisella LPS have revealed substantial differences when compared to more commonly studied LPSs of the Enterobacteriaceae. This review discusses both the general characteristics and the unusual features of Francisella LPS.

  structure, O-antigen, lipid A, Francisella tularensis, Kdo hydrolase, lipopolysachharide

  NCBI PubMed ID: 23916469
  Publication DOI: 10.1016/j.carres.2013.06.015
  Journal NLM ID: 0043535
  Publisher: Elsevier
  Correspondence: D.L. Kasper
  Institutions: Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA
  
   
  
  Francisella tularensis ssp. tularensis SCHU S4, Francisella tularensis 15, Francisella tularensis OSU10, Francisella tularensis ssp. holarctica LVS
  CSDB ID 29667 (all data & tools)
• Article ID: 4697
  Lu Z, Rynkiewicz MJ, Yang CY, Madico G, Perkins HM, Roche MI, Seaton BA, Sharon J "Functional and Structural Characterization of Francisella tularensis O-Antigen Antibodies at the Low End of Antigen Reactivity" - Monoclonal Antibodies in Immunodiagnosis and Immunotherapy 33(4) (2014) 235-245
  

  The O-antigen (OAg) of the Gram-negative bacterium Francisella tularensis (Ft), which is both a capsular polysaccharide and a component of lipopolysaccharide, is comprised of tetrasaccharide repeats and induces antibodies mainly against repeating internal epitopes. We previously reported on several BALB/c mouse monoclonal antibodies (MAbs) that bind to internal Ft OAg epitopes and are protective in mouse models of respiratory tularemia. We now characterize three new internal Ft OAg IgG2a MAbs, N203, N77, and N24, with 10- to 100-fold lower binding potency than previously characterized internal-OAg IgG2a MAbs, despite sharing one or more variable region germline genes with some of them. In a mouse model of respiratory tularemia with the highly virulent Ft type A strain SchuS4, the three new MAbs reduced blood bacterial burden with potencies that mirror their antigen-binding strength; the best binder of the new MAbs, N203, prolonged survival in a dose-dependent manner, but was at least 10-fold less potent than the best previously characterized IgG2a MAb, Ab52. X-ray crystallographic studies of N203 Fab showed a flexible binding site in the form of a partitioned groove, which cannot provide as many contacts to OAg as does the Ab52 binding site. These results reveal structural features of antibodies at the low end of reactivity with multi-repeat microbial carbohydrates and demonstrate that such antibodies still have substantial protective effects against infection.

  capsular polysaccharide, antibodies, monoclonal antibodies, Gram-negative bacteria, tularemia, BALB/c mouse, epitopeFrancisella tularensis

  NCBI PubMed ID: 25171003
  Publication DOI: 10.1089/mab.2014.0022
  Journal NLM ID: 101590955
  Publisher: New Rochelle, NY: Mary Ann Liebert, Inc.
  Correspondence: jsharon@bu.edu
  Institutions: Department of Pathology and Laboratory Medicine, Boston University School of Medicine , Boston, Massachusetts
  Methods: X-ray, ELISA, Western blotting, biological assays, RT-PCR, binding assays
  
   
  
  Francisella tularensis, Francisella tularensis ssp. holarctica LVS
  CSDB ID 30096 (all data & tools)
• Article ID: 4920
  Chen L, Valentine JL, Huang CJ, Endicott CE, Moeller TD, Rasmussen JA, Fletcher JR, Boll JM, Rosenthal JA, Dobruchowska J, Wang Z, Heiss C, Azadi P, Putnam D, Trent MS, Jones BD, DeLisa MP "Outer membrane vesicles displaying engineered glycotopes elicit protective antibodies" - Proceedings of the National Academy of Sciences of the USA 113(26) (2016) E3609-E3618
  

  The O-antigen polysaccharide (O-PS) component of lipopolysaccharides on the surface of gram-negative bacteria is both a virulence factor and a B-cell antigen. Antibodies elicited by O-PS often confer protection against infection; therefore, O-PS glycoconjugate vaccines have proven useful against a number of different pathogenic bacteria. However, conventional methods for natural extraction or chemical synthesis of O-PS are technically demanding, inefficient, and expensive. Here, we describe an alternative methodology for producing glycoconjugate vaccines whereby recombinant O-PS biosynthesis is coordinated with vesiculation in laboratory strains of Escherichia coli to yield glycosylated outer membrane vesicles (glycOMVs) decorated with pathogen-mimetic glycotopes. Using this approach, glycOMVs corresponding to eight different pathogenic bacteria were generated. For example, expression of a 17-kb O-PS gene cluster from the highly virulent Francisella tularensis subsp. tularensis (type A) strain Schu S4 in hypervesiculating E. coli cells yielded glycOMVs that displayed F. tularensis O-PS. Immunization of BALB/c mice with glycOMVs elicited significant titers of O-PS-specific serum IgG antibodies as well as vaginal and bronchoalveolar IgA antibodies. Importantly, glycOMVs significantly prolonged survival upon subsequent challenge with F. tularensis Schu S4 and provided complete protection against challenge with two different F. tularensis subsp. holarctica (type B) live vaccine strains, thereby demonstrating the vaccine potential of glycOMVs. Given the ease with which recombinant glycotopes can be expressed on OMVs, the strategy described here could be readily adapted for developing vaccines against many other bacterial pathogens.

  glycan, glycoconjugate vaccine, O-antigen polysaccharide, anti-glycan antibodies, humoral immune response, outer membrane vesicle

  NCBI PubMed ID: 27274048
  Publication DOI: 10.1073/pnas.1518311113
  Journal NLM ID: 7505876
  Publisher: National Academy of Sciences
  Correspondence: md255@cornell.edu
  Institutions: Complex Carbohydrate Research Center, The University of Georgia, Athens, GA 30602, Department of Microbiology, University of Iowa, Iowa City, IA 52242, Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, Department of Infectious Diseases, The University of Georgia College of Veterinary Medicine, Athens, GA 30602, Genetics Program, University of Iowa, Iowa City, IA 52242, Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853
  Methods: 13C NMR, 1H NMR, NMR-2D, sugar analysis, ELISA, Western blotting, MALDI-TOF MS, biological assays, NMR-1D, serological methods, genetic methods, electron microscopy, SEC, immunization
  
   
  
  Francisella tularensis ssp. tularensis Schu S4
  CSDB ID 11304 (all data & tools)
• Article ID: 5188
  Micoli F, Costantino P, Adamo R "Potential targets for next generation anti-microbial glycoconjugate vaccines" - FEMS Microbiology Reviews 42(3) (2018) 388-423
  

  Cell surface carbohydrates have been proven optimal targets for vaccine development. Conjugation of polysaccharides to a carrier protein triggers a T-cell dependent immune response to the glycan moiety. Licensed glycoconjugate vaccines are produced by chemical conjugation of capsular polysaccharides to prevent meningitis caused by meningococcus, pneumococcus and Haemophilus influenzae type b. However, other classes of carbohydrates (O-antigens, exopolysaccharides, wall/teichoic acids) represent attractive targets for developing vaccines.Recent analysis from WHO/CHO underpins alarming concern towards antibiotic resistant bacteria, such as the so called ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp.) and additional pathogens such as Clostridium difficile and Group A Streptococcus. Fungal infections are also becoming increasingly invasive for immunocompromised patients or hospitalized individuals. Other emergencies could derive from bacteria which spread during environmental calamities (Vibrio cholerae) or with potential as bioterrorism weapons (Burkholderia pseudomallei and mallei, Francisella tularensis). Vaccination could aid reducing the use of broad spectrum antibiotics and provide protection by herd immunity also to individuals who are not vaccinated.This review analyses structural and functional differences of the polysaccharides exposed on the surface of emerging pathogenic bacteria, combined with medical need and technological feasibility of corresponding glycoconjugate vaccines.

  carbohydrates, glycoconjugates, vaccines, glycoengineering, antimicrobial resistance

  NCBI PubMed ID: 29547971
  Publication DOI: 10.1093/femsre/fuy011
  Journal NLM ID: 8902526
  Publisher: Oxford University Press
  Correspondence: Roberto Adamo
  Institutions: GSK Vaccines Institute for Global Health (GVGH), Via Fiorentina 1, 53100 Siena
  
   
  
  Francisella tularensis
  CSDB ID 12698 (all data & tools)
• Article ID: 5791
  Knirel YA, Van Calsteren M "Bacterial exopolysaccharides" - Book: Comprehensive Glycoscience: From Chemistry to Systems Biology. Reference Module in Chemistry, Molecular Sciences and Chemical Engineering (2021) 1-75
  

  Bacterial extracellular polysaccharides are known as a cell-bound capsule, a sheath, or a slime, which is excreted into the environment. They play an important role in virulence of medical bacteria and plant-to-symbiont interaction and are used for serotyping of bacteria and production of vaccines. Some exopolysaccharides have commercial applications in industry, and claims of health benefits have been documented for an increasing number of them. Exopolysaccharides have diverse composition and structure, and some contain sugar and non-sugar components that are found in bacterial carbohydrates only. The present article provides an updated collection of the data on exopolysaccharides of various classes of gram-negative and gram-positive bacteria reported until the end of 2019. When known, biosynthesis pathways of exopolysaccharides are treated in a summary manner. References are made to structure and biosynthesis relatedness between exopolysaccharides of different bacterial taxa as well as between bacterial polysaccharides and mammalian glycosaminoglycans.

  polysaccharide structure, Gram-negative bacteria, capsule, Biofilm, polysaccharide biosynthesis, gram-positive bacteria, Monosaccharide composition, Bacterial exopolysaccharide, non-sugar component

  Publication DOI: 10.1016/B978-0-12-819475-1.00005-5
  Publisher: Elsevier
  Correspondence: marie-rose.vancalsteren@canada.ca; yknirel@gmail.com
  Editors: Barchi J, Kamerling H
  Institutions: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia, Saint-Hyacinthe Research and Development Centre, Agriculture and Agri-Food Canada, Saint-Hyacinthe, QC, Canada
  
   
  
  Francisella tularensis SCHU S4
  CSDB ID 6765 (all data & tools)
• Article ID: 6301
  Qin CJ, Ding MR, Tian GZ, Zou XP, Fu JJ, Hu J, Yin J "Chemical approaches towards installation of rare functional groups in bacterial surface glycans" - Chinese Journal of Natural Medicines = Zhongguo Tianran Yaowu 20(6) (2022) 401-420
  

  Bacterial surface glycans perform a diverse and important set of biological roles, and have been widely used in the treatment of bacterial infectious diseases. The majority of bacterial surface glycans are decorated with diverse rare functional groups, including amido, acetamidino, carboxamido and pyruvate groups. These functional groups are thought to be important constituents for the biological activities of glycans. Chemical synthesis of glycans bearing these functional groups or their variants is essential for the investigation of structure-activity relationships by a medicinal chemistry approach. To date, a broad choice of synthetic methods is available for targeting the different rare functional groups in bacterial surface glycans. This article reviews the structures of naturally occurring rare functional groups in bacterial surface glycans, and the chemical methods used for installation of these groups.

  chemical synthesis, acetamidino group, amido group, bacterial surface glycan, carboxamido group, pyruvyl ketal

  NCBI PubMed ID: 35750381
  Publication DOI: 10.1016/S1875-5364(22)60177-8
  Journal NLM ID: 101504416
  Publisher: Beijing: Science Press; Elsevier
  Correspondence: J. Yin
  Institutions: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China, Wuxi School of Medicine, Jiangnan University, Wuxi, China
  
   
  
  Francisella tularensis 15
  CSDB ID 9115 (all data & tools)
• Article ID: 6318
  Srtefanetti G, Maclennan CA, Micoli F "Impact and Control of Sugar Size in Glycoconjugate Vaccines" - Molecules 27(19) (2022) 6432
  

  Glycoconjugate vaccines have contributed enormously to reducing and controlling encapsulated bacterial infections for over thirty years. Glycoconjugate vaccines are based on a carbohydrate antigen that is covalently linked to a carrier protein; this is necessary to cause T cell responses for optimal immunogenicity, and to protect young children. Many interdependent parameters affect the immunogenicity of glycoconjugate vaccines, including the size of the saccharide antigen. Here, we examine and discuss the impact of glycan chain length on the efficacy of glycoconjugate vaccines and report the methods employed to size polysaccharide antigens, while highlighting the underlying reaction mechanisms. A better understanding of the impact of key parameters on the immunogenicity of glycoconjugates is critical to developing a new generation of highly effective vaccines.

  glycoconjugates, vaccine, immunogenicity, fragmentation of polysaccharides, sugar length

  NCBI PubMed ID: 36234967
  Publication DOI: 10.3390/molecules27196432
  Journal NLM ID: 100964009
  Publisher: Basel, Switzerland: MDPI
  Correspondence: G. Srtefanetti
  Institutions: Department of Biomolecular Sciences, University of Urbino Carlo Bo, 61029 Urbino, Italy, Enteric and Diarrheal Diseases, Global Health, Bill & Melinda Gates Foundation, 500 5th Ave. N, Seattle, WA 98109, USA, The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7DQ, UK, The Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, UK, GSK Vaccines Institute for Global Health, 53100 Siena, Italy
  
   
  
  Francisella tularensis
  CSDB ID 8820 (all data & tools)

Show legend Show as text

Structure type: polymer chemical repeating unit
Aglycon: core
Compound class: O-polysaccharide, O-antigen
Contained glycoepitopes: IEDB_151083,IEDB_221847,IEDB_221848

• Article ID: 3402
  Gunn JS, Ernst RK "The structure and function of Francisella lipopolysaccharide" - Annals of the New York Academy of Sciences 1105 (2007) 202-218
  

  A key factor in the biology of Francisella spp. is lipopolysaccharide (LPS). Francisella LPS has many unique structural properties and poorly activates proinflammatory responses due to its lack of interaction with toll-like receptor 4 (TLR4). The LPS of this organism can be modified by various carbohydrates including glucose, mannose and galactosamine, which affect various aspects of virulence. Spontaneously occurring colony variants of F. tularensis have altered LPS. This altered LPS may account for the novel phenotypes of these variants that include effects on susceptibility to killing by normal human serum, intracellular survival and animal virulence. Mutants devoid of O-antigen (directed mutants in O-antigen biosynthetic genes) show reduced intracellular survival and mouse virulence. Thus, this surface component is important in F. tularensis pathogenesis, and the inability of the LPS to alarm the immune system coupled with its frequent modification/alteration likely aid the success of this pathogen during human infection

  Lipopolysaccharide, LPS, Phase variation, O-antigen, lipid A, variant, Francisella, gray variant, LPS modification, LPS structure

  NCBI PubMed ID: 17395723
  Journal NLM ID: 7506858
  Publisher: New York Academy of Sciences
  Correspondence: gunn.43@osu.edu
  Institutions: The Center for Microbial Interface Biology, The Ohio State University, Biomedical Research Tower, Rm. 1006, 460 W. 12th Ave., Columbus, OH 43210-1214, USA
  Methods: 13C NMR, 1H NMR, NMR-2D, GLC-MS, 31P NMR, GLC, chemical methods, MALDI-TOF MS, NMR-1D, serological methods, genetic methods, CE-ESI-MS
  
   
  
  Francisella tularensis Schu S4, Francisella tularensis OSU10, Francisella holartica LVS 15
  CSDB ID 21565 (all data & tools)

Show legend Show as text

Structure type: polymer chemical repeating unit ; 25000-80000
Compound class: O-antigen
Contained glycoepitopes: IEDB_151083,IEDB_221847,IEDB_221848

• Article ID: 5540
  Stefanetti G, Okan N, Fink A, Gardner E, Kasper DL "Glycoconjugate vaccine using a genetically modified O antigen induces protective antibodies to Francisella tularensis" - Proceedings of the National Academy of Sciences of the USA 116(14) (2019) 7062-7070
  

  Francisella tularensis is the causative agent of tularemia, a category A bioterrorism agent. The lipopolysaccharide (LPS) O antigen (OAg) of F. tularensis has been considered for use in a glycoconjugate vaccine, but conjugate vaccines tested so far have failed to confer protection necessary against aerosolized pulmonary bacterial challenge. When F. tularensis OAg was purified under standard conditions, the antigen had a small molecular size [25 kDa, low molecular weight (LMW)]. Using milder extraction conditions, we found the native OAg had a larger molecular size [80 kDa, high molecular weight (HMW)], and in a mouse model of tularemia, a glycoconjugate vaccine made with the HMW polysaccharide coupled to tetanus toxoid (HMW-TT) conferred better protection against intranasal challenge than a conjugate made with the LMW polysaccharide (LMW-TT). To further investigate the role of OAg size in protection, we created an F. tularensis live vaccine strain (LVS) mutant with a significantly increased OAg size [220 kDa, very high molecular weight (VHMW)] by expressing in F. tularensis a heterologous chain-length regulator gene (wzz) from the related species Francisella novicida Immunization with VHMW-TT provided markedly increased protection over that obtained with TT glycoconjugates made using smaller OAgs. We found that protective antibodies recognize a length-dependent epitope better expressed on HMW and VHMW antigens, which bind with higher affinity to the organism.

  O antigen, Francisella, glycoconjugate vaccine, intracellular pathogen, antibody affinity

  NCBI PubMed ID: 30872471
  Publication DOI: 10.1073/pnas.1900144116
  Journal NLM ID: 7505876
  Publisher: National Academy of Sciences
  Correspondence: D.L. Kasper
  Institutions: Department of Immunology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, Department of Microbiology, Evelo Biosciences, Cambridge, MA 02139, The Lautenberg Center for Immunology and Cancer Research, Hebrew University-Hadassah Medical School, 91120 Jerusalem, Israel, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115
  Methods: 1H NMR, SDS-PAGE, DNA techniques, ELISA, biological assays, serological methods, HPSEC, immunoblotting, immunization, conjugation
  
   
  
  Francisella tularensis LVS
  CSDB ID 2687 (all data & tools)