لخّصلي

Translocation of CagA into host gastric epithelial cells by H. pylori is achieved via a specific interaction between surface adhesins of the bacteria and receptors for the bacterial component on the host cells.

Translocation of CagA into host gastric epithelial cells by H. pylori is achieved via a specific interaction between surface adhesins of the bacteria and receptors for the bacterial component on the host cells. In recent studies, carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) have been identified as a set of protein receptors on epithelial cells that are essential for CagA delivery, which is mediated by specific binding of CEACAMs with the outer membrane adhesin HopQ of the bacteria.50,51,59,60 The CagL protein, a pilus surface component of the T4SS, has also been reported to be an adhesin that mediates CagA delivery by interacting with and thereby activating ɑ5β1 integrin on target gastric epithelial cells in an arginine-glycine-aspartate (RGD) motif-dependent manner.61 CagL stimulates SRC family kinase (SFK) activity, which in turn phosphorylates the delivered CagA.61 The ɑ5β1 integrin also interacts with other components of the T4SS, including CagY and CagI, which may cooperatively stabilize the T4SS-host cell interaction.62 To further facilitate the delivery of CagA, H. pylori induces the membrane phospholipid phosphatidylserine (PS) found in the inner membrane leaflet of epithelial cells to be exposed on the outer membrane.63 CagA interacts with the exposed PS to initiate its secretion into the host epithelial cell.63