CX3C chemokine mimicry by respiratory syncytial virus G glycoprotein

Chemokines are chemoattractant proteins that are divided into subfamilies based upon cysteine signature motifs termed C, CC, CXC and CX3C. Chemokines have roles in immunity and inflammation that affect cell trafficking and activation of T cells as well as cells of the innate immune system. We report here CX3C chemokine mimicry for the G glycoprotein of respiratory syncytial virus (RSV) and show binding to CX3CRI-the specific receptor for the CX3C chemokine fractalkine-and induction of leukocyte chemotaxis. We also show that CX3CRI facilitates RSV infection of cells. Thus, G glycoprotein interaction with CX3CRI probably plays a key role in the biology of RSV infection.