CD147 is a signaling receptor for cyclophilin B

Cyclophilins A and B (CyPA and CyPB) are cyclosporin A binding proteins tha t can be secreted in response to inflammatory stimuli. We recently identifi ed CD147 as a cell-surface receptor for CyPA and demonstrated that CD147 is an essential component in the CyPA-initiated signaling cascade that culmin ates in ERK activation and chemotaxis. Here we demonstrate that CD147 also serves as a receptor for CyPB. CyPB induced Ca2+ flux and chemotaxis of CD1 47-transfected, but not control, CHO cells, and the chemotactic response of primary human neutrophils to CyPB was blocked by antibodies to CD147. Thes e results suggest that CD147 serves as a receptor for extracellular cycloph ilins. (C) 2001 Academic Press.