IDENTIFICATION OF THE CC CHEMOKINES TARC AND MACROPHAGE INFLAMMATORY PROTEIN-1-BETA AS NOVEL FUNCTIONAL LIGANDS FOR THE CCR8 RECEPTOR

Chemokines are key molecules in directing leukocyte migration toward s ites of inflammation. We have previously cloned a putative CC chemokin e receptor gene, TER1, whose expression is restricted to lymphoid tiss ues and cell lines. Recently, this receptor has been shown to Signal i n response to the human CC chemokine I-309 and thus it has been rename d CCR8 according to the current nomenclature. In the present study, we report the identification of the CC chemokines thymus and activation- regulated cytokine (TARC) and macrophage inflammatory protein-1 beta ( MIP-1 beta) as CCR8 ligands, as they induce chemotaxis in CCR8 Jurkat stable transfectants, Furthermore, we have generated a polyclonal anti serum that is able to recognize the CCR8 molecule in transfectant lysa tes. the pattern of CCR8 mRNA expression and the functional effects ex erted by its ligand suggest that the triggering of this receptor may r egulate multiple functions including activation, migration and prolife ration of lymphoid cells.