Lipopolysaccharide structures of Helicobacter pylori genomic strains 26695and J99, mouse model H-pylori Sydney strain, H-pylori P466 carrying sialylLewis X, and H-pylori UA915 expressing Lewis B - Classification of H-pylori lipopolysaccharides into glycotype families

This study describes the molecular makeup of the cell-wall lipopolysacchari des (LPSs) (O-chain polysaccharide-->core oligosaccharide-->lipid A) from f ive Helicobacter pylori strains: H. pylori 26695 and J99, the complete geno me sequences of which have been published, the established mouse model Sydn ey strain (SS1), and the symptomatic strains P466 and UA915. All chemical a nd serological experiments were performed on the intact LPSs. H. pylori 266 95 and SS1 possessed either a low-M, semi-rough-form LPS carrying mostly a single Le(y) type-2 blood-group determinant in the O-chain region covalentl y attached to the core oligosaccharide or a high-M-r smooth-form LPS, as di d strain J99, with an elongated partially fucosylated type-2 N-acetyllactos amine (polyLacNAc) O-chain polymer, terminated mainly by a Le(x) blood-grou p determinant, connected to the core oligosaccharide. In the midst of semi- rough-form LPS glycoforms, H. pylori 26695 and SS1 also expressed in the O- chain region a difucosylated antigen, alpha-L-Fucp(1-3)-alpha-L-Fucp(1-4)-b eta-D-GlcpNAc, and the cancer-cell-related type-1 or type-2 linear B-blood- group antigen, alpha-D-Galp(1-3)-beta-D-Galp(1-3 or 4)-beta-D-GlcpNAc. The LPS of H. pylori strain P466 carried the cancer-associated type-2 sialyl Le (x) blood-group antigen, and the LPS from strain UA915 expressed a type-1 L e(b) blood-group unit. These findings should aid investigations that focus on identifying and characterizing genes responsible for LPS biosynthesis in genomic strains 26695 and J99, and in understanding the role of H. pylori LPS in animal model studies. The LPSs from the H. pylori strains studied to date were grouped into specific glycotype families.