A new role for CCR5 in innate immunity--binding to bacterial heat shock protein 70.

CCR5 has been associated with adaptive immune responses, because of its expression on effector and memory T cells, and dentric cells. In this issue of the European Journal of Immunology, Whittall et al. identify CCR5 as a receptor that binds bacterial heat shock protein 70 (HSP70). Thus HSP70 may stimulate responses by CCR5+ T cells or dendritic cells, particularly at epithelial surfaces. These findings imply a role for CCR5 in innate immunity, in addition to its more established role as a chemoattractant receptor for adaptive immune responses.