Heterophilic chemokine receptor interactions in chemokine signaling and biology.

It is generally accepted that G-protein coupled receptors (GPCR), like chemokine receptors, form dimers or higher order oligomers. Such homo- and heterophilic interactions have been identified not only among and between chemokine receptors of CC- or CXC-subfamilies, but also between chemokine receptors and other classes of GPCR, like the opioid receptors. Oligomerization affects different aspects of receptor physiology, like ligand affinity, signal transduction and the mode of internalization, in turn influencing physiologic processes such as cell activation and migration. As particular chemokine receptor pairs exert specific modulating effects on their individual functions, they might play particular roles in various disease types, such as cancer. Hence, chemokine receptor heteromers might represent attractive therapeutic targets. This review highlights the state-of-the-art knowledge on the technical and functional aspects of chemokine receptor multimerization in chemokine signaling and biology.