H Pylori Binds to Stomach Cell Glycolipid

Researchers have identified the mechanism by which Helicobacter pylori, the bacterium responsible for gastric ulcers and possibly some types of stomach cancer, adheres to the cells lining the stomach and avoids attack by the host immune system. Their findings were published in the July 26, 2002, issue of Science.

Working with a strain of H pylori that lacks the gene for synthesis of the sialic-acid binding adhesin protein (SabA), investigators from Washington University (St. Louis, MO, USA) showed that a specific glycolipid produced by cells of the inflamed stomach lining was necessary for H pylori binding.

They identified sialyl-dimeric-Lewis x glycosphingolipid as a receptor for H pylori and showed that H pylori infection induced formation of sialyl-Lewis x antigens in gastric epithelium in humans and in a Rhesus monkey. The corresponding sialic acid-binding adhesin (SabA) was isolated with the "retagging” method, and the underlying sabA gene (JHP662/HP0725) was identified.

"These findings should improve our understanding of how H pylori infection happens, how our immune system responds to it, and how the bacteria cope with that response,” said Dr. Douglas E. Berg, professor of molecular microbiology at the Washington University School of Medicine. "We also hope that understanding how these adhesins work will lead to a vaccine against H pylori infections and to new drugs to treat or diminish their severity.”




Related Links:
Washington Univ.