Show legend Show as text

Structure type: polymer chemical repeating unit
Trivial name: cell-surface polysaccharide, hexaglycosyl phosphate repeating unit cell-surface polysaccharide, PSII
Compound class: CPS, cell wall polysaccharide
Contained glycoepitopes: IEDB_130648,IEDB_130701,IEDB_137473,IEDB_142488,IEDB_144983,IEDB_144996,IEDB_144998,IEDB_146664,IEDB_152206,IEDB_189516,IEDB_241118,IEDB_983930,IEDB_983931,SB_192,SB_44,SB_67,SB_72

• Article ID: 3470
  Ganeshapillai J, Vinogradov E, Rousseau J, Weese JS, Monteiro MA "Clostridium difficile cell-surface polysaccharides composed of pentaglycosyl and hexaglycosyl phosphate repeating units" - Carbohydrate Research 343(4) (2008) 703-710
  

  Clostridium difficile is a Gram-positive bacterium that is known to be a cause of enteric diseases in humans. It is the leading cause of antibiotic-associated diarrhea and pseudomembranous colitis. Recently, large outbreaks of C. difficile-associated diarrhea have been reported internationally, and there have been reports of increases in severe disease, mortality and relapse rates. At the moment, there is no vaccine against C. difficile, and the medical prevention of C. difficile infection is mostly based on the prophylactic use of antibiotics; however, this has led to an increase in the incidence of the disease. Here, we describe the chemical structure of C. difficile cell-surface polysaccharides. The polysaccharides of three C. difficile strains were structurally analyzed; ribotype 027 (North American pulsotype 1) strain was observed to express two polysaccharides, one was composed of a branched pentaglycosyl phosphate repeating unit: [→4)-α-L-Rhap-(1→3)-β-D-Glcp-(1→4)-[α-L-Rhap-(1→3]-α-D-Glcp-(1→2)-α-D-Glcp-(1→P] and the other was composed of a hexaglycosyl phosphate repeating unit: [→6)-β-D-Glcp-(1→3)-β-D-GalpNAc-(1→4)-α-D-Glcp-(1→4)-[β-D-Glcp-(1→]-β-D-GalpNAc-(1→3)-α-D-Manp-(1→P]. The latter polysaccharide was also observed to be produced by strains MOH900 and MOH718. The results described here represent the first literature report describing the covalent chemical structures of C. difficile cell-surface polysaccharides, of which PS-II appears to be a regular C. difficile antigen. These C. difficile teichoic-acid-like polysaccharides will be tested as immunogens in vaccine preparations in a rat and horse model.

  Structural characterization, Clostridium difficile, Teichoic-acid polysaccharide

  NCBI PubMed ID: 18237724
  Publication DOI: 10.1016/j.carres.2008.01.002
  Journal NLM ID: 0043535
  Publisher: Elsevier
  Correspondence: monteiro@uoguelph.ca
  Institutions: Department of Chemistry, University of Guelph, Guelph, ON, Canada N1G 2W1
  Methods: 13C NMR, 1H NMR, NMR-2D, GC-MS, 31P NMR, composition analysis
  
   
  
  Clostridium difficile O27, Clostridium difficile MOH900, Clostridium difficile MOH718
  CSDB ID 22950 (all data & tools)
• Article ID: 4275
  Bertolo L, Boncheff AG, Ma Z, Chen YH, Wakeford T, Friendship RM, Rosseau J, Weese JS, Chu M, Mallozzi M, Vedantam G, Monteiro MA "Clostridium difficile carbohydrates: glucan in spores, PSII common antigen in cells, immunogenicity of PSII in swine and synthesis of a dual C. difficile-ETEC conjugate vaccine" - Carbohydrate Research 354 (2012) 79-86
  

  Clostridium difficile is responsible for severe diarrhea in humans that may cause death. Spores are the infectious form of C. difficile, which germinate into toxin-producing vegetative cells in response to bile acids. Recently, we discovered that C. difficile cells possess three complex polysaccharides (PSs), named PSI, PSII, and PSIII, in which PSI was only associated with a hypervirulent ribotype 027 strain, PSII was hypothesized to be a common antigen, and PSIII was a water-insoluble polymer. Here, we show that (i) C. difficile spores contain, at least in part, a D-glucan, (ii) PSI is not a ribotype 027-unique antigen, (iii) common antigen PSII may in part be present as a low molecular weight lipoteichoic acid, (iv) selective hydrolysis of PSII yields single PSII repeat units, (v) the glycosyl diester-phosphate linkage affords high flexibility to PSII, and (vi) that PSII is immunogenic in sows. Also, with the intent of creating a dual anti-diarrheal vaccine against C. difficile and enterotoxin Escherichia coli (ETEC) infections in humans, we describe the conjugation of PSII to the ETEC-associated LTB enterotoxin.

  conjugate vaccine, glucan, Clostridium difficile, spores, PSI, PSII

  NCBI PubMed ID: 22533919
  Publication DOI: 10.1016/j.carres.2012.03.032
  Journal NLM ID: 0043535
  Publisher: Elsevier
  Correspondence: monteiro@uoguelph.ca (M.A. Monteiro)
  Institutions: Department of Chemistry, University of Guelph, Guelph, ON, Canada
  Methods: 13C NMR, 1H NMR, NMR-2D, GC-MS, SDS-PAGE, sugar analysis, 31P NMR, MD simulations, immunochemical methods, conjugation
  
   
  
  Clostridium difficile 027, Clostridium difficile 001
  CSDB ID 27119 (all data & tools)
• Article ID: 4378
  Reid CW, Vinogradov E, Li J, Jarrell HC, Logan SM, Brisson JR "Structural characterization of surface glycans from Clostridium difficile" - Carbohydrate Research 354 (2012) 65-73
  

  Whole-cell high-resolution magic angle spinning (HR-MAS) NMR was employed to survey the surface polysaccharides of a group of clinical and environmental isolates of Clostridium difficile. Results indicated that a highly conserved surface polysaccharide profile among all strains studied. Multiple additional peaks in the anomeric region were also observed which prompted further investigation. Structural characterization of the isolated surface polysaccharides from two strains confirmed the presence of the conserved water soluble polysaccharide originally described by Ganeshapillai et al. which was composed of a hexaglycosyl phosphate repeat consisting of [→6)-β-D-Glcp-(1-3)-β-D-GalpNAc-(1-4)-α-D-Glcp-(1-4)-[β-D-Glcp(1-3]-β-D-GalpNAc-(1-3)-α-D-Manp-(1-P→]. In addition, analysis of phenol soluble polysaccharides revealed a similarly conserved lipoteichoic acid (LTA) which could be detected on whole cells by HR-MAS NMR. Conventional NMR and mass spectrometry analysis indicated that the structure of this LTA consisted of the repeat unit [→6)-α-D-GlcpNAc-(1-3)-[→P-6]-α-D-GlcpNAc-(1-2)-D-GroA] where GroA is glyceric acid. The repeating units were linked by a phosphodiester bridge between C-6 of the two GlcNAc residues (6-P-6). A minor component consisted of GlcpN-(1-3) instead of GlcpNAc-(1-3) in the repeat unit. Through a 6-6 phosphodiester bridge this polymer was linked to →6)-β-D-Glcp-(1-6)-β-D-Glcp-(1-6)-β-D-Glcp-(1-1)-Gro, with glycerol (Gro) substituted by fatty acids. This is the first report of the utility of HR-MAS NMR in the examination of surface carbohydrates of Gram positive bacteria and identification of a novel LTA structure from Clostridium difficile.

  capsular polysaccharide, lipoteichoic acid, Clostridium difficile, lipocarbohydrate, High-resolution magic angle spinning (HRMAS) NMR

  NCBI PubMed ID: 22560631
  Publication DOI: 10.1016/j.carres.2012.02.002
  Journal NLM ID: 0043535
  Publisher: Elsevier
  Correspondence: S.M. Logan
  Institutions: National Research Council-Institute for Biological Sciences, 100 Sussex Drive, Ottawa, ON, Canada K1A 0R6
  Methods: 13C NMR, 1H NMR, de-O-acylation, sugar analysis, 31P NMR, HF treatment, CE-MS/MS, HR-MAS NMR
  
   
  
  Clostridium difficile O27, Clostridium difficile, Clostridium difficile O630, Clostridium difficile CM26
  CSDB ID 27293 (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
  
   
  
  Clostridium difficile
  CSDB ID 12688 (all data & tools)
• Article ID: 5740
  Campanero-Rhodes MA, Palma AS, Menendez M, Solis D "Microarray Strategies for Exploring Bacterial Surface Glycans and Their Interactions With Glycan-Binding Proteins" - Frontiers in Microbiology 10 (2020) 2909
  

  Bacterial surfaces are decorated with distinct carbohydrate structures that may substantially differ among species and strains. These structures can be recognized by a variety of glycan-binding proteins, playing an important role in the bacteria cross-talk with the host and invading bacteriophages, and also in the formation of bacterial microcolonies and biofilms. In recent years, different microarray approaches for exploring bacterial surface glycans and their recognition by proteins have been developed. A main advantage of the microarray format is the inherent miniaturization of the method, which allows sensitive and high-throughput analyses with very small amounts of sample. Antibody and lectin microarrays have been used for examining bacterial glycosignatures, enabling bacteria identification and differentiation among strains. In addition, microarrays incorporating bacterial carbohydrate structures have served to evaluate their recognition by diverse host/phage/bacterial glycan-binding proteins, such as lectins, effectors of the immune system, or bacterial and phagic cell wall lysins, and to identify antigenic determinants for vaccine development. The list of samples printed in the arrays includes polysaccharides, lipopoly/lipooligosaccharides, (lipo)teichoic acids, and peptidoglycans, as well as sequence-defined oligosaccharide fragments. Moreover, microarrays of cell wall fragments and entire bacterial cells have been developed, which also allow to study bacterial glycosylation patterns. In this review, examples of the different microarray platforms and applications are presented with a view to give the current state-of-the-art and future prospects in this field.

  antibodies, immune system, lectins, vaccine development, microarrays, bacterial glycans, bacterial interactions

  NCBI PubMed ID: 32010066
  Publication DOI: 10.3389/fmicb.2019.02909
  Journal NLM ID: 101548977
  Publisher: Lausanne: Frontiers Research Foundation
  Correspondence: Dolores Solis
  Institutions: Instituto de Quimica Fisica Rocasolano, Consejo Superior de Investigaciones Cientificas, Madrid, Spain, Centro de Investigacion Biomedica en Red de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain, UCIBIO, Department of Chemistry, Faculty of Science and Technology, NOVA University of Lisbon, Lisbon, Portuga
  
   
  
  Clostridium difficile
  CSDB ID 3282 (all data & tools)
• Article ID: 6211
  Del Bino L, Osterlid KE, Wu DY, Nonne F, Romano MR, Codée J, Adamo R "Synthetic Glycans to Improve Current Glycoconjugate Vaccines and Fight Antimicrobial Resistance" - Chemical Reviews 122(20) (2022) 15672-15716
  

  Antimicrobial resistance (AMR) is emerging as the next potential pandemic. Different microorganisms, including the bacteria Acinetobacter baumannii, Clostridioides difficile, Escherichia coli, Enterococcus faecium, Klebsiella pneumoniae, Neisseria gonorrhoeae, Pseudomonas aeruginosa, non-typhoidal Salmonella, and Staphylococcus aureus, and the fungus Candida auris, have been identified by the WHO and CDC as urgent or serious AMR threats. Others, such as group A and B Streptococci, are classified as concerning threats. Glycoconjugate vaccines have been demonstrated to be an efficacious and cost-effective measure to combat infections against Haemophilus influenzae, Neisseria meningitis, Streptococcus pneumoniae, and, more recently, Salmonella typhi. Recent times have seen enormous progress in methodologies for the assembly of complex glycans and glycoconjugates, with developments in synthetic, chemoenzymatic, and glycoengineering methodologies. This review analyzes the advancement of glycoconjugate vaccines based on synthetic carbohydrates to improve existing vaccines and identify novel candidates to combat AMR. Through this literature survey we built an overview of structure-immunogenicity relationships from available data and identify gaps and areas for further research to better exploit the peculiar role of carbohydrates as vaccine targets and create the next generation of synthetic carbohydrate-based vaccines.

  carbohydrates, glycan, glycoconjugate vaccine

  NCBI PubMed ID: 35608633
  Publication DOI: 10.1021/acs.chemrev.2c00021
  Journal NLM ID: 2985134R
  Publisher: Chem Rev
  Correspondence: J. Codée ; R. Adamo
  Institutions: GSK, R&D, 53100 Siena, Italy, Leiden Institute of Chemistry, Leiden University, 2300 RA Leiden, The Netherlands
  
   
  
  Clostridioides difficile
  CSDB ID 20887 (all data & tools)

Show legend Show as text

Structure type: oligomer
Aglycon: CRM197 (diphteria toxin)
Contained glycoepitopes: IEDB_130648,IEDB_130701,IEDB_137473,IEDB_142488,IEDB_144983,IEDB_144998,IEDB_146664,IEDB_152206,IEDB_189516,IEDB_241118,IEDB_983930,IEDB_983931,SB_192,SB_44,SB_67,SB_72

• Article ID: 4267
  Adamo R, Romano MR, Berti F, Leuzzi R, Tontini M, Danieli E, Cappelletti E, Cakici OS, Swennen E, Pinto V, Brogioni B, Proietti D, Galeotti CL, Lay L, Monteiro MA, Scarselli M, Costantino P "Phosphorylation of the Synthetic Hexasaccharide Repeating Unit Is Essential for the Induction of Antibodies to Clostridium difficile PSII Cell Wall Polysaccharide" - ACS Chemical Biology 7(8) (2012) 1420-1428
  

  Clostridium difficile is emerging worldwide as a major cause of nosocomial infections. The negatively charged PSII polysaccharide has been found in different strains of C. difficile and, thereby, represents an important target molecule for a possible carbohydrate-based vaccine. In order to identify a synthetic fragment that after conjugation to a protein carrier could be able to induce anti-PSII antibodies, we exploited a combination of chemical synthesis with immunochemistry, confocal immunofluorescence microscopy, and solid state NMR. We demonstrate that the phosphate group is crucial in synthetic glycans to mimic the native PSII polysaccharide; both native PSII and a phosphorylated synthetic hexasaccharide repeating unit conjugated to CRM(197) elicit comparable immunogenic responses in mice. This finding can aid design and selection of carbohydrate antigens to be explored as vaccine candidates.

  NMR, synthesis, vaccines, cell wall polysaccharide, CRM(197), Clostridium difficile

  NCBI PubMed ID: 22620974
  Publication DOI: 10.1021/cb300221f
  Journal NLM ID: 101282906
  Publisher: Washington, DC: American Chemical Society
  Correspondence: roberto.adamo@novartis.com
  Institutions: Research Center, Novartis Vaccines and Diagnostics , Via Fiorentina 1, 53100 Siena, Italy
  Methods: 13C NMR, 1H NMR, SDS-PAGE, TLC, ELISA, 31P NMR, MALDI-TOF MS, NMR-1D, immunochemical methods, HPAEC-PAD, HR-MAS NMR, immunofluorescence microscopy, conjugation
  
   
  
  Clostridium difficile
  CSDB ID 28303 (all data & tools)

Show legend Show as text

Structure type: oligomer
Aglycon: CRM197 (diphteria toxin)
Contained glycoepitopes: IEDB_130648,IEDB_130701,IEDB_137473,IEDB_142488,IEDB_144983,IEDB_144998,IEDB_146664,IEDB_152206,IEDB_189516,IEDB_983930,IEDB_983931,SB_192,SB_44,SB_67,SB_72

• Article ID: 4267
  Adamo R, Romano MR, Berti F, Leuzzi R, Tontini M, Danieli E, Cappelletti E, Cakici OS, Swennen E, Pinto V, Brogioni B, Proietti D, Galeotti CL, Lay L, Monteiro MA, Scarselli M, Costantino P "Phosphorylation of the Synthetic Hexasaccharide Repeating Unit Is Essential for the Induction of Antibodies to Clostridium difficile PSII Cell Wall Polysaccharide" - ACS Chemical Biology 7(8) (2012) 1420-1428
  

  Clostridium difficile is emerging worldwide as a major cause of nosocomial infections. The negatively charged PSII polysaccharide has been found in different strains of C. difficile and, thereby, represents an important target molecule for a possible carbohydrate-based vaccine. In order to identify a synthetic fragment that after conjugation to a protein carrier could be able to induce anti-PSII antibodies, we exploited a combination of chemical synthesis with immunochemistry, confocal immunofluorescence microscopy, and solid state NMR. We demonstrate that the phosphate group is crucial in synthetic glycans to mimic the native PSII polysaccharide; both native PSII and a phosphorylated synthetic hexasaccharide repeating unit conjugated to CRM(197) elicit comparable immunogenic responses in mice. This finding can aid design and selection of carbohydrate antigens to be explored as vaccine candidates.

  NMR, synthesis, vaccines, cell wall polysaccharide, CRM(197), Clostridium difficile

  NCBI PubMed ID: 22620974
  Publication DOI: 10.1021/cb300221f
  Journal NLM ID: 101282906
  Publisher: Washington, DC: American Chemical Society
  Correspondence: roberto.adamo@novartis.com
  Institutions: Research Center, Novartis Vaccines and Diagnostics , Via Fiorentina 1, 53100 Siena, Italy
  Methods: 13C NMR, 1H NMR, SDS-PAGE, TLC, ELISA, 31P NMR, MALDI-TOF MS, NMR-1D, immunochemical methods, HPAEC-PAD, HR-MAS NMR, immunofluorescence microscopy, conjugation
  
   
  
  Clostridium difficile
  CSDB ID 28304 (all data & tools)

Show legend Show as text

Structure type: polymer chemical repeating unit ; n=8,11,21
Compound class: cell wall polysaccharide
Contained glycoepitopes: IEDB_130648,IEDB_130701,IEDB_137473,IEDB_142488,IEDB_144983,IEDB_144996,IEDB_144998,IEDB_146664,IEDB_152206,IEDB_189516,IEDB_241118,IEDB_983930,IEDB_983931,SB_192,SB_44,SB_67,SB_72

• Article ID: 4267
  Adamo R, Romano MR, Berti F, Leuzzi R, Tontini M, Danieli E, Cappelletti E, Cakici OS, Swennen E, Pinto V, Brogioni B, Proietti D, Galeotti CL, Lay L, Monteiro MA, Scarselli M, Costantino P "Phosphorylation of the Synthetic Hexasaccharide Repeating Unit Is Essential for the Induction of Antibodies to Clostridium difficile PSII Cell Wall Polysaccharide" - ACS Chemical Biology 7(8) (2012) 1420-1428
  

  Clostridium difficile is emerging worldwide as a major cause of nosocomial infections. The negatively charged PSII polysaccharide has been found in different strains of C. difficile and, thereby, represents an important target molecule for a possible carbohydrate-based vaccine. In order to identify a synthetic fragment that after conjugation to a protein carrier could be able to induce anti-PSII antibodies, we exploited a combination of chemical synthesis with immunochemistry, confocal immunofluorescence microscopy, and solid state NMR. We demonstrate that the phosphate group is crucial in synthetic glycans to mimic the native PSII polysaccharide; both native PSII and a phosphorylated synthetic hexasaccharide repeating unit conjugated to CRM(197) elicit comparable immunogenic responses in mice. This finding can aid design and selection of carbohydrate antigens to be explored as vaccine candidates.

  NMR, synthesis, vaccines, cell wall polysaccharide, CRM(197), Clostridium difficile

  NCBI PubMed ID: 22620974
  Publication DOI: 10.1021/cb300221f
  Journal NLM ID: 101282906
  Publisher: Washington, DC: American Chemical Society
  Correspondence: roberto.adamo@novartis.com
  Institutions: Research Center, Novartis Vaccines and Diagnostics , Via Fiorentina 1, 53100 Siena, Italy
  Methods: 13C NMR, 1H NMR, SDS-PAGE, TLC, ELISA, 31P NMR, MALDI-TOF MS, NMR-1D, immunochemical methods, HPAEC-PAD, HR-MAS NMR, immunofluorescence microscopy, conjugation
  
   
  
  Clostridium difficile M68, Clostridium difficile M120, Clostridium difficile R20291, Clostridium difficile 630, Clostridium difficile NF2023
  CSDB ID 28305 (all data & tools)

Show legend Show as text

Structure type: oligomer
Trivial name: repeating unit CPS
Compound class: CPS
Contained glycoepitopes: IEDB_130648,IEDB_130701,IEDB_137473,IEDB_142488,IEDB_144983,IEDB_144998,IEDB_146664,IEDB_152206,IEDB_189516,IEDB_983930,IEDB_983931,SB_192,SB_44,SB_67,SB_72

• Article ID: 4378
  Reid CW, Vinogradov E, Li J, Jarrell HC, Logan SM, Brisson JR "Structural characterization of surface glycans from Clostridium difficile" - Carbohydrate Research 354 (2012) 65-73
  

  Whole-cell high-resolution magic angle spinning (HR-MAS) NMR was employed to survey the surface polysaccharides of a group of clinical and environmental isolates of Clostridium difficile. Results indicated that a highly conserved surface polysaccharide profile among all strains studied. Multiple additional peaks in the anomeric region were also observed which prompted further investigation. Structural characterization of the isolated surface polysaccharides from two strains confirmed the presence of the conserved water soluble polysaccharide originally described by Ganeshapillai et al. which was composed of a hexaglycosyl phosphate repeat consisting of [→6)-β-D-Glcp-(1-3)-β-D-GalpNAc-(1-4)-α-D-Glcp-(1-4)-[β-D-Glcp(1-3]-β-D-GalpNAc-(1-3)-α-D-Manp-(1-P→]. In addition, analysis of phenol soluble polysaccharides revealed a similarly conserved lipoteichoic acid (LTA) which could be detected on whole cells by HR-MAS NMR. Conventional NMR and mass spectrometry analysis indicated that the structure of this LTA consisted of the repeat unit [→6)-α-D-GlcpNAc-(1-3)-[→P-6]-α-D-GlcpNAc-(1-2)-D-GroA] where GroA is glyceric acid. The repeating units were linked by a phosphodiester bridge between C-6 of the two GlcNAc residues (6-P-6). A minor component consisted of GlcpN-(1-3) instead of GlcpNAc-(1-3) in the repeat unit. Through a 6-6 phosphodiester bridge this polymer was linked to →6)-β-D-Glcp-(1-6)-β-D-Glcp-(1-6)-β-D-Glcp-(1-1)-Gro, with glycerol (Gro) substituted by fatty acids. This is the first report of the utility of HR-MAS NMR in the examination of surface carbohydrates of Gram positive bacteria and identification of a novel LTA structure from Clostridium difficile.

  capsular polysaccharide, lipoteichoic acid, Clostridium difficile, lipocarbohydrate, High-resolution magic angle spinning (HRMAS) NMR

  NCBI PubMed ID: 22560631
  Publication DOI: 10.1016/j.carres.2012.02.002
  Journal NLM ID: 0043535
  Publisher: Elsevier
  Correspondence: S.M. Logan
  Institutions: National Research Council-Institute for Biological Sciences, 100 Sussex Drive, Ottawa, ON, Canada K1A 0R6
  Methods: 13C NMR, 1H NMR, de-O-acylation, sugar analysis, 31P NMR, HF treatment, CE-MS/MS, HR-MAS NMR
  
   
  
  Clostridium difficile 630, Clostridium difficile CM26, Clostridium difficile
  CSDB ID 28605 (all data & tools)

Show legend Show as text

Structure type: suggested polymer biological repeating unit
Trivial name: PSII
Compound class: cell wall polysaccharide
Contained glycoepitopes: IEDB_130648,IEDB_130701,IEDB_137473,IEDB_142488,IEDB_144983,IEDB_144996,IEDB_144998,IEDB_146664,IEDB_152206,IEDB_189516,IEDB_241118,IEDB_983930,IEDB_983931,SB_192,SB_44,SB_67,SB_72

• Article ID: 5812
  Ma Z, Zhang GL, Gadi MR, Guo Y, Wang P, Li L "Clostridioides difficile cd2775 Encodes a Unique Mannosyl-1-Phosphotransferase for Polysaccharide II Biosynthesis" - ACS Infectious Diseases 6(4) (2020) 680-686
  

  Clostridioides difficile (C. difficile) is the leading cause of antibiotic-induced bacterial colitis and life-threatening diarrhea worldwide. The commonly existing anionic polysaccharide II (PSII) is responsible for protein anchoring involved in colonization, and the gene cd2775 located in its biosynthesis gene cluster is essential for bacterial growth. Herein, we demonstrated that cd2775 encodes a novel mannosyl-1-phosphotransferase (ManPT) responsible for the phosphorylation of PSII. Unlike typical mannosyltransferases, CD2775 transfers mannose-α1-phosphate instead of mannose from guanosine 5'-diphospho-d-mannose to disaccharide acceptors, forming a unique mannose-α1-phosphate-6-glucose linkage. The enzyme was overexpressed in E. coli and purified for biochemical characterization and substrate specificity study. It is found that CD2775 possesses a strict acceptor specificity toward Glc-β1,3-GalNAc-diphospho-lipids but extreme promiscuity toward various sugar donors. This is the first report of a ManPT in all living systems. Given its essentiality in C. difficile growth, CD2775 can be a promising target for therapeutics development.

  Substrate Specificity, CD2775, Clostridioides difficile, mannosyl-1-phosphotransferase, polysaccharide II

  NCBI PubMed ID: 32073825
  Publication DOI: 10.1021/acsinfecdis.9b00494
  Journal NLM ID: 101654580
  Publisher: Washington, DC: American Chemical Society
  Correspondence: lli22@gsu.edu
  Institutions: Department of Chemistry , Georgia State University , 50 Decatur Street SE , Atlanta , Georgia 30303 , United States
  Methods: SDS-PAGE, kinetics assays, MALDI-MS, Western blotting, genetic methods, bioinformatic analysis, enzymatic synthesis, enzymatic assay
  
   
  
  Clostridioides difficile
  CSDB ID 32157 (all data & tools)

Show legend Show as text

Structure type: oligomer
Aglycon: (->1)(CH2)3NH2 (3-aminopropyl)
Trivial name: PSII
Compound class: cell wall polysaccharide
Contained glycoepitopes: IEDB_130648,IEDB_130701,IEDB_137473,IEDB_142488,IEDB_144983,IEDB_144998,IEDB_146664,IEDB_152206,IEDB_189516,IEDB_241118,IEDB_983930,IEDB_983931,SB_192,SB_44,SB_67,SB_72

• Article ID: 5812
  Ma Z, Zhang GL, Gadi MR, Guo Y, Wang P, Li L "Clostridioides difficile cd2775 Encodes a Unique Mannosyl-1-Phosphotransferase for Polysaccharide II Biosynthesis" - ACS Infectious Diseases 6(4) (2020) 680-686
  

  Clostridioides difficile (C. difficile) is the leading cause of antibiotic-induced bacterial colitis and life-threatening diarrhea worldwide. The commonly existing anionic polysaccharide II (PSII) is responsible for protein anchoring involved in colonization, and the gene cd2775 located in its biosynthesis gene cluster is essential for bacterial growth. Herein, we demonstrated that cd2775 encodes a novel mannosyl-1-phosphotransferase (ManPT) responsible for the phosphorylation of PSII. Unlike typical mannosyltransferases, CD2775 transfers mannose-α1-phosphate instead of mannose from guanosine 5'-diphospho-d-mannose to disaccharide acceptors, forming a unique mannose-α1-phosphate-6-glucose linkage. The enzyme was overexpressed in E. coli and purified for biochemical characterization and substrate specificity study. It is found that CD2775 possesses a strict acceptor specificity toward Glc-β1,3-GalNAc-diphospho-lipids but extreme promiscuity toward various sugar donors. This is the first report of a ManPT in all living systems. Given its essentiality in C. difficile growth, CD2775 can be a promising target for therapeutics development.

  Substrate Specificity, CD2775, Clostridioides difficile, mannosyl-1-phosphotransferase, polysaccharide II

  NCBI PubMed ID: 32073825
  Publication DOI: 10.1021/acsinfecdis.9b00494
  Journal NLM ID: 101654580
  Publisher: Washington, DC: American Chemical Society
  Correspondence: lli22@gsu.edu
  Institutions: Department of Chemistry , Georgia State University , 50 Decatur Street SE , Atlanta , Georgia 30303 , United States
  Methods: SDS-PAGE, kinetics assays, MALDI-MS, Western blotting, genetic methods, bioinformatic analysis, enzymatic synthesis, enzymatic assay
  
   
  
  Clostridioides difficile
  CSDB ID 3842 (all data & tools)

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Structure type: polymer chemical repeating unit ; -P-6)bDGlcp(1-3)[Ac(1-2)]bDGalpN(1-4)aDGlcp(1-4)[bDGlcp(1-3),Ac(1-2)]bDGalpN(1-3)aDManp(1-
Trivial name: cell-surface polysaccharide
Compound class: CPS
Contained glycoepitopes: IEDB_130648,IEDB_130701,IEDB_137473,IEDB_142488,IEDB_144983,IEDB_144996,IEDB_144998,IEDB_146664,IEDB_152206,IEDB_189516,IEDB_241118,IEDB_983930,IEDB_983931,SB_192,SB_44,SB_67,SB_72

• Article ID: 6046
  Cox AD, St Michael F, Aubry A, Strong PCR, Hayes AC, Logan SM "Comparison of polysaccharide glycoconjugates as candidate vaccines to combat Clostridiodes (Clostridium) difficile" - Glycoconjugate Journal 38(4) (2021) 493-508
  

  Two known Clostridiodes (Clostridium) difficile surface antigens, a lipoteichoic acid (LTA) and a polysaccharide (PS-II) were isolated and purified in order to prepare glycoconjugate vaccines to the carrier protein human serum albumin utilising a reductive amination strategy. Mice and rabbits were immunized with a prime and two boost strategy and the resulting sera were examined for their ability to recognise the purified homologous antigens and subsequently killed whole cells of C. difficile strains and other Clostridia species. Immunisation derived antisera from rabbits and mice, recognised all strains of C. difficile vegetative cells examined, with generally similar titers from animals that received the LTA or the PS-II conjugates. Sera raised to the LTA conjugates were able to recognise other Clostridia species C. butyricum, C. bifermentans and C. subterminale whereas sera raised to the PS-II conjugates were not. These LTA and PS-II sera recognised live cells in an immunofluorescence assay and were also able to recognise the spore form of the bacterium. This study has confirmed that the LTA and PS-II polysaccharides are both highly conserved surface polymers of C. difficile that are easily accessible to the immune system and as such may have potential as vaccine antigens or as targets for therapeutics to combat C. difficile infection.

  conjugate vaccine, lipoteichoic acid, capsular polysaccharide PS-II, Clostridiodes difficile

  NCBI PubMed ID: 32789783
  Publication DOI: 10.1007/s10719-020-09937-9
  Journal NLM ID: 8603310
  Publisher: Kluwer Academic Publishers
  Correspondence: AD Cox
  Institutions: Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, K1A 0R6, Canada
  Methods: 1H NMR, SDS-PAGE, ELISA, Western blotting, MALDI-TOF MS, de-O-acetylation, HPLC, periodate oxidation, immunization, conjugation, reductive amination, immunofluorescence
  
   
  
  Clostridium difficile 630
  CSDB ID 10839 (all data & tools)

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Structure type: oligomer
Aglycon: spacer-CRM197
Trivial name: repeating unit conjugate
Compound class: cell wall polysaccharide
Contained glycoepitopes: IEDB_130648,IEDB_130701,IEDB_137473,IEDB_142488,IEDB_144983,IEDB_144998,IEDB_146664,IEDB_152206,IEDB_189516,IEDB_241118,IEDB_983930,IEDB_983931,SB_192,SB_44,SB_67,SB_72

• Article ID: 6211
  Del Bino L, Osterlid KE, Wu DY, Nonne F, Romano MR, Codée J, Adamo R "Synthetic Glycans to Improve Current Glycoconjugate Vaccines and Fight Antimicrobial Resistance" - Chemical Reviews 122(20) (2022) 15672-15716
  

  Antimicrobial resistance (AMR) is emerging as the next potential pandemic. Different microorganisms, including the bacteria Acinetobacter baumannii, Clostridioides difficile, Escherichia coli, Enterococcus faecium, Klebsiella pneumoniae, Neisseria gonorrhoeae, Pseudomonas aeruginosa, non-typhoidal Salmonella, and Staphylococcus aureus, and the fungus Candida auris, have been identified by the WHO and CDC as urgent or serious AMR threats. Others, such as group A and B Streptococci, are classified as concerning threats. Glycoconjugate vaccines have been demonstrated to be an efficacious and cost-effective measure to combat infections against Haemophilus influenzae, Neisseria meningitis, Streptococcus pneumoniae, and, more recently, Salmonella typhi. Recent times have seen enormous progress in methodologies for the assembly of complex glycans and glycoconjugates, with developments in synthetic, chemoenzymatic, and glycoengineering methodologies. This review analyzes the advancement of glycoconjugate vaccines based on synthetic carbohydrates to improve existing vaccines and identify novel candidates to combat AMR. Through this literature survey we built an overview of structure-immunogenicity relationships from available data and identify gaps and areas for further research to better exploit the peculiar role of carbohydrates as vaccine targets and create the next generation of synthetic carbohydrate-based vaccines.

  carbohydrates, glycan, glycoconjugate vaccine

  NCBI PubMed ID: 35608633
  Publication DOI: 10.1021/acs.chemrev.2c00021
  Journal NLM ID: 2985134R
  Publisher: Chem Rev
  Correspondence: J. Codée ; R. Adamo
  Institutions: GSK, R&D, 53100 Siena, Italy, Leiden Institute of Chemistry, Leiden University, 2300 RA Leiden, The Netherlands
  
   
  
  Clostridioides difficile
  CSDB ID 20890 (all data & tools)