Structure and biological functions of Helicobacter pylori lipopolysaccharide
Helicobacter pylori (H.pylori) infection is one of the most common chronic infectious diseases in humans. It is the leading cause of chronic gastritis and peptic ulcer, and also the most important risk factor for gastric cancer. H. pylori lipopolysaccharide has unique chemical structures that are critical to the persistent infection and pathogenesis of H. pylori in human gastric mucosa. Recent studies have elucidated the H. pylori lipid A constitutive modification pathway, redefined the core-oligosaccharide and O-antigen domains, discovered that the heptan commonly present in the lipopolysaccharide structure of European strains is absent in East Asian strains and more importantly, the identification of ADP-heptose (the donor of heptose residues in lipopolysaccharide structure) as the newly discovered pathogen-associated molecular pattern, which is dependent on the type Ⅳ secretion system of H. pylori to induce inflammatory responses in host cells. This paper reviewed the resent research progress in the structure and biological functions of H. pylori lipopolysaccharide. 
 
 
Key words: 
Helicobacter pylori; Lipopolysaccharide; Heptose; ADP-heptose