Identification of a novel chemokine (CCL28), which binds CCR10 (GPR2)

We report the identification and characterization of a novel CC chemokine d esignated CCL28 and its receptor CCR10, known previously as orphan G-protei n-coupled receptor GPR2. Human and mouse CCL28 share 83% identity at the am ino acid and 76% at the nucleic acid levels. We also identified the mouse h omologues of CCL28 and of CCR10, which map to mouse chromosomes 13 and 11, respectively, CCL28 is expressed in a variety of human and mouse tissues, a nd it appears to be predominantly produced by epithelial cells. Both human and mouse CCL28 induce calcium mobilization in human and mouse CCL28 expres sing transfectants. CCL28 desensitized the calcium mobilization induced in CCR10 transfectants by CCL27, indicating that these chemokines share this n ew chemokine receptor. In vitro, recombinant human CCL28 displays chemotact ic activity for resting CD4 or CD8 T cells.