Molecular Pathology

O-glycans that protect stomach from Helicobacter pylori infection
(Department of Molecular Pathology: Masatomo Kawakubo, Yuki Ito, Jun Nakayama, et al.)

Helicobacter pylori (H. pylori) infects nearly a half of the human population. However, it is well known that most infected individuals remain asymptomatic, suggesting that there is a host defense mechanism against this bacterium. H. pylori is associated solely with surface mucin secreted by the surface mucous cells, but it is rarely found in gland mucin secreted by deeper portion of the gastric mucosa. The gland mucin contains unique O-glycans having terminal a1,4-linked N-acetylglucosamine. Recently, we discovered that these O-glycans have antimicrobial activity against H. pylori, inhibiting its biosynthesis of cholesteryl-a-D-glucopyranoside, a major cell wall component. Since the gastric mucin is essentially equipped with the O-glycans, it appeared to function as a natural antibiotic, thus protecting the host from H. pylori infection. Our results provide a basis for development of novel and potentially safe therapeutic agents to prevent and treat H. pylori infection in humans without adverse reactions.