Abstract

Epithelia form barriers that are essential to life. This is particularly true in oral and GI mucosal tissues that are constantly exposed to dietary and environmental antigens and the resident and foreign bacterial flora. For a barrier to exist, the intercellular space need be maintained and this is accomplished by the organization of the tight junction (TJ) complex. The multi-molecular TJ complex forms a belt at the apical portions of cells and is best divided into three groups: (i) integral TJ proteins that form strands which bridge the intercellular space and consist of proteins such…