Preferential involvement of CX chemokine receptor 4 and CX chemokine ligand 12 in T-cell migration toward melanoma cells.

Our previous analysis of the role of chemokines in T lymphocyte trafficking toward human tumor cells revealed the migration of a melanoma patient's cytotoxic T lymphocytes (CTL) toward autologous tumor cells, resulting in tumor cell apoptosis, in an organotypic melanoma culture. CTL migration was mediated by CX chemokine receptor (CXCR) 4 expressed by the CTL and CX chemokine ligand (CXCL) 12 secreted by the tumor cells, as evidenced by blockage of CTL migration by antibodies to CXCL12 or CXCR4, high concentrations of CXCL12 or small molecule CXCR4 antagonist. Here, we present the results of T cell migration in one additional melanoma patient and T cell and tumor cell analyses for CXCR4 and CXCL12 expression, respectively, in 12 additional melanoma patients, indicating the preferential role of CXCR4 and CXCL12 in CTL migration toward melanoma cells. These studies add to the increasing body of evidence suggesting that CXCL12 is a potent chemoattractant for T cells.