Structure of the lipopolysaccharide O-antigens from Fusobacterium nucleatum strains SB-106CP and HM-992 and immunological comparison to the O-antigen of strain 12230

• Published in: Carbohydrate research Vol. 517; p. 108576
• Main Authors: Vinogradov, Evgeny, Michael, Frank St, Cairns, Chantelle, Cox, Andrew D.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.07.2022
• Subjects: Fusobacterium nucleatum; Lipopolysaccharide; NMR spectroscopy; Polysaccharide structure; Lipopolysaccharide; Fusobacterium nucleatum; NMR spectroscopy; Polysaccharide structure
• ISSN: 0008-6215; 1873-426X
• DOI: 10.1016/j.carres.2022.108576

Fusobacterium nucleatum is an anaerobic bacterium found in the human mouth where it causes periodontitis. It was also found in colorectal cancer tissues and is linked with pregnancy complications, including pre-term and stillbirths. Cell surface structures of the bacterium could be implicated in pathogenesis. Here we report the structures of the lipopolysaccharide O-chain (OPS) of two strains of F. nucleatum, SB-106CP and HM-992, both isolated from cancerous tissues. These strains elaborate the same sugar chain, differing only by their N-acylation pattern: -6-α-D-GlcNAc-4-β-D-GlcNHBu3NABuA-3-β-D-QuiNAc4NABuAc- SB-106CP -6-α-D-GlcNAc-4-β-D-GlcNHBu3NABuA-3-β-D-QuiNAc4NAc- HM-992 ABu = (R)-3-amino-butyryl AbuAc = (R)-3-N-acetyl-3-aminobutyryl HBu = (R)-3-hydroxy-butyryl All monosaccharides are in the pyranose form. Previously we published the structure of the OPS from F. nucleatum 12230, a transtracheal isolate, which had similar sugar chain, differing by replacement of GlcNAc with Glc and a different acylation pattern: -6-α-d-Glc-4-β-d-GlcNHBu3NHBuA-3-β-d-QuiNAc4NABu- A mouse monoclonal antibody specific for the 12230 O-antigen did not cross react with the LPS of strains SB-106CP and HM-992 confirming the structural differentiation. [Display omitted] •Fusobacterium nucleatum is human pathogen and cancer-accociated bacterium.•Bacterial surface structures are possibly implicated in disease.•Here we present the structures of two carbohydrate antigens of F. nucleatum.•Both structures contain unusual sugars and acyl groups.