EFFECTS OF HELICOBACTER-PYLORI VACUOLATING CYTOTOXIN ON PRIMARY CULTURES OF HUMAN GASTRIC EPITHELIAL-CELLS

Background-Many Helicobacter pylori strains produce a cytotoxin that i nduces cytoplasmic vacuolation in various types of eukaryotic cells. I n contrast with the marked cell vacuolation that occurs in vitro in re sponse to this cytotoxin, comparatively Little epithelial vacuolation has been observed in the gastric mucosa of H pylori infected persons. Aims-Experiments were performed to determine the susceptibility of hum an gastric epithelial cells in vitro to H pylori vacuolating cytotoxin activity. Methods-Human gastric epithelial cells, harvested from uppe r gastrointestinal endoscopic biopsy specimens, were incubated overnig ht with broth culture supernatants from either a wild type cytotoxin p roducing (tox(+)) H pylori strain or an isogenic mutant strain that la cks cytotoxin activity. Results-Prominent cytoplasmic vacuolation occu rred in response to tox(+) supernatant, but not supernatant from the i sogenic mutant strain. Primary human gastric epithelial cells were sig nificantly more sensitive to H pylori vacuolating cytotoxin activity t han were either HeLa or AGS cells, Exposure of human gastric epithelia l cells to high concentrations of tox(+) supernatant for 48 hours caus ed lethal cell injury. Conclusions-These studies indicate that primary human gastric epithelial cells are highly sensitive to H pylori vacuo lating cytotoxin activity.