Type 1 and 2 Lewis antigens of Helicobacter pylori – a potential marker of the human geographical distribution

ABSTRACTLewis (Le) antigens are fucosylated oligosaccharides present in theHelicobacter pylorilipopolysaccharide. Expression of these antigens is believed to be important forH. pyloricolonization, since Le antigens also are expressed on the gastric epithelia in humans. A galactosyltransferase encoded by β-(1,3)galTis essential for production of type 1 (Leaand Leb) antigens. The upstream genejhp0562, which is present in many but not allH. pyloristrains, is homologous to β-(1,3)galTbut is of unknown function. BecauseH. pyloridemonstrates extensive intragenomic recombination, we hypothesized that these two genes could undergo DNA rearrangement. A PCR screen and subsequent sequence analyses revealed that the two genes can recombine at both the 5′ and 3′ ends. Chimeric β-(1,3)galT-like alleles can restore function in a β-(1,3)galTnull mutant, but neither native nor recombinantjhp0562can. Mutagenesis ofjhp0562revealed that it is essential for synthesis of both type 1 and type 2 Le antigens. Transcriptional analyses of both loci showed β-(1,3)galTexpression in all wild-type (WT) and mutant strains tested, whereasjhp0562was not expressed injhp0562null mutants, as expected. Sincejhp0562unexpectedly displayed functions in both type 1 and type 2 Le synthesis, we asked whethergalT, part of the type 2 synthesis pathway, had analogous functions in type 1 synthesis. Mutagenesis and complementation analysis confirmed thatgalTis essential for Lebproduction. In total, these results demonstrate thatgalTandjhp0562have functions that cross the expected Le synthesis pathways and thatjhp0562provides a substrate for intragenomic recombination to generate diverse Le synthesis enzymes.

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Helicobacter pylori–binding nonacid glycosphingolipids in the human stomach

Journal of Biological Chemistry ◽

10.1074/jbc.ra118.004854 ◽

2018 ◽

Vol 293 (44) ◽

pp. 17248-17266 ◽

Cited By ~ 6

Author(s):

Chunsheng Jin ◽

Angela Barone ◽

Thomas Borén ◽

Susann Teneberg

Keyword(s):

Helicobacter Pylori ◽

Gastric Mucosa ◽

Structural Complexity ◽

Human Stomach ◽

Carbohydrate Binding ◽

Human Gastric Mucosa ◽

H Pylori ◽

Contrast Information

Helicobacter pylori has a number of well-characterized carbohydrate-binding adhesins (BabA, SabA, and LabA) that promote adhesion to the gastric mucosa. In contrast, information on the glycoconjugates present in the human stomach remains unavailable. Here, we used MS and binding of carbohydrate-recognizing ligands to characterize the glycosphingolipids of three human stomachs from individuals with different blood group phenotypes (O(Rh−)P, A(Rh+)P, and A(Rh+)p), focusing on compounds recognized by H. pylori. We observed a high degree of structural complexity, and the composition of glycosphingolipids differed among individuals with different blood groups. The type 2 chain was the dominating core chain of the complex glycosphingolipids in the human stomach, in contrast to the complex glycosphingolipids in the human small intestine, which have mainly a type 1 core. H. pylori did not bind to the O(Rh−)P stomach glycosphingolipids, whose major complex glycosphingolipids were neolactotetraosylceramide, the Lex, Lea, and H type 2 pentaosylceramides, and the Ley hexaosylceramide. Several H. pylori-binding compounds were present among the A(Rh+)P and A(Rh+)p stomach glycosphingolipids. Ligands for BabA-mediated binding of H. pylori were the Leb hexaosylceramide, the H type 1 pentaosylceramide, and the A type 1/ALeb heptaosylceramide. Additional H. pylori-binding glycosphingolipids recognized by BabA-deficient strains were lactosylceramide, lactotetraosylceramide, the x2 pentaosylceramide, and neolactohexaosylceramide. Our characterization of human gastric receptors required for H. pylori adhesion provides a basis for the development of specific compounds that inhibit the binding of this bacterium to the human gastric mucosa.

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Biomarkers of bone metabolism in horses: Ante-mortem versus post-mortem correlation in serum and aqueous humour

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.1055/s-0038-1632716 ◽

2002 ◽

Vol 15 (02) ◽

pp. 67-71

Author(s):

L. T. Glickman ◽

N. W. Glickman ◽

E. S. Rasmussen ◽

S. J. Carlson ◽

G. J. Breur ◽

...

Keyword(s):

Alkaline Phosphatase ◽

Bone Metabolism ◽

Aqueous Humour ◽

Bone Alkaline Phosphatase ◽

Serum Marker ◽

Post Mortem ◽

Potential Marker ◽

Serum Ictp

SummaryThe objective of this study was to determine the correlation between ante-mortem and 24-hour postmortem concentrations of four markers of bone metabolism in equine serum and aqueous humour. The markers evaluated were osteocalcin, bone alkaline phosphatase, carboxyterminal propeptide of type-1 procollagen and carboxyterminal cross-linked telopeptide of type-1 collagen (ICTP). The concentrations of these markers were poorly correlated (P > 0.05) between aqueous humour and serum. ICTP was the only serum marker significantly correlated (r = 0.93) between ante- and post-mortem samples. ICTP is, therefore, a potential marker for evaluating antemortem markers of bone metabolism in dead horses.

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