Figure 1.

Models of S. aureus adherence to and invasion of epithelial cells. (A) Adherence of S. aureus to epithelial cell surface is mediated by clumping factor B (ClfB) through high affinity interactions with cytokeratin 10 and loricrin. Iron-regulated surface determinant A (IsdA) protein further contributes to epithelial adherence by binding to the cornified cell envelope protein loricrin, involucrin and cytokeratin 10. Wall theicoic acid (WTA) glycopolymer has been also proposed to promote staphylococcal adhesion through an epithelial type F scavenger receptor named SREC-I. (B) Fibronectin-binding proteins A and B bind to the extracellular matrix fibronectin which interacts with integrin α₅β₁ on the surface of epithelial cells, thereby triggering invasion of the cells. Recently, it has been suggested that clumping factor A (ClfA) bind to surface-associated annexin A2, and this interaction could mediate S. aureus internalization into mammary epithelial cells.