Type IV secretion of Helicobacter pylori CagA into oral epithelial cells is prevented by the absence of CEACAM receptor expression.

These results show that lack of CEACAM receptors on the surface of the oral epithelial cells was responsible for resistance to H. pylori CagA-dependent pathogenic activities, and confirms the important role for the T4SS-dependent interaction of these receptors with H. pylori in the gastric epithelium.