Galectin-3 binds to Helicobacter pylori O-antigen: it is upregulated and rapidly secreted by gastric epithelial cells in response to H. pylori adhesion

Cell Microbiol. 2006 Jan;8(1):44-54. doi: 10.1111/j.1462-5822.2005.00599.x.


Helicobacter pylori causes gastritis and some infections result in peptic ulceration, gastric adenocarcinoma or gastric lymphoma. A critical step in the pathogenesis of these diseases is the ability of H. pylori to adhere to gastric epithelial cells. A role for the lipopolysaccharide O-antigen side-chain in this process has previously been identified. In this study, evidence is presented that the receptor recognized by the O-antigen side-chain is galectin-3, a beta-galactoside-binding lectin. A variety of functions have been ascribed to galectin-3 including modulation of extracellular adhesion and chemotaxis of monocytes and neutrophils. Expression of galectin-3 is upregulated by gastric epithelial cells following adhesion of H. pylori, suggesting that in addition to colonization this protein also plays a role in the host response to infection. Upregulation of galectin-3 is inhibited by treating gastric epithelial cells with the mitogen-activated protein kinase (MAPK) inhibitors U0126 or PD098059 and does not occur in cells infected with either H. pylori cagE or cagA isogenic mutants. This implies that H. pylori-mediated expression of galectin-3 is dependent on delivery of CagA into the host cell cytosol and the subsequent stimulation of MAPK signalling. A further consequence of H. pylori adhesion is that it elicits a rapid release of galectin-3 from infected cells. A role for this phenomenon in initiating the trafficking of phagocytic cells to the site of infection is discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Bacterial / physiology
  • Bacterial Adhesion*
  • Bacterial Proteins / physiology
  • Cell Line
  • Chlorocebus aethiops
  • Epithelial Cells / metabolism*
  • Epithelial Cells / microbiology
  • Galectin 3 / biosynthesis
  • Galectin 3 / metabolism*
  • Gastric Mucosa / cytology
  • Gastric Mucosa / metabolism*
  • Gastric Mucosa / microbiology
  • Helicobacter pylori / genetics
  • Helicobacter pylori / physiology*
  • Humans
  • O Antigens / metabolism*
  • Protein Binding
  • RNA, Messenger / biosynthesis
  • Up-Regulation


  • Antigens, Bacterial
  • Bacterial Proteins
  • Galectin 3
  • O Antigens
  • RNA, Messenger
  • cagA protein, Helicobacter pylori