Cross-talk between Fc receptors and integrins.

Fc receptors (FcRs) and integrins are both key players of immune responses. These receptors are capable of independent signaling that leads to various cell functions. Recently, it is becoming clear that these receptors are also capable of modulating each other's responses. This modulation is achieved by direct physical interactions of the receptors on the cell surface, or by one receptor modifying the signaling pathway of the other receptor. Receptor co-localization and resonance energy transfer studies have shown that Fc receptors and integrins interact on the cell surface. Biochemical and functional studies have shown that signaling from Fc receptors modulates integrin adhesiveness through a process called "inside-out signaling". Other studies also show that the signaling from integrins modulates Fc receptor responses such as adhesion to immune complexes and cell mediated antibody-dependent cytotoxicity. This bi-directional cross-talk between Fc receptors and integrins is very important for the final cell function. Here, we review the latest information about interactions between Fc receptors and integrins.