Non-signaling chemokine receptors: Mechanism of action and role in vivo

Cell migration is fundamental for numerous biological processes and is critical for the pathogenesis of several diseases. Chemokines represent the main class of mediators providing cell directional migration and several levels of regulation of their function have been identified. A subfamily of chemokine receptors not able to transduce chemotactic signals plays an important role in the control of chemokine concentrations through binding, internalization and degradation of chemotactic factors. Here we review in vitro and in vivo evidences indicating that these 'silent' chemokine receptors represent a strategy to regulate innate and adaptive immunity.