CX3C chemokine mimicry by respiratory syncytial virus G glycoprotein

Chemokines are chemoattractant proteins that are divided into subfamilies b ased upon cysteine signature motifs termed C, CC, CXC and CX3C. Chemokines have roles in immunity and inflammation that affect cell trafficking and ac tivation of T cells as well as cells of the innate immune system. We report here CX3C chemokine mimicry for the G glycoprotein of respiratory syncytia l 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 intera ction with CX3CRI probably plays a key role in the biology of RSV infection .