CD56⁺CD3⁺CD16^– NK T cells migrate better in response to CXCL12 than do CD56⁺CD16⁺CD3^– NK cells. (A) The migration of CD56⁺ cells in response to the chemokine CXCL12 (100-500 ng/mL) is inhibited by pretreatment of cells with 1000 IU/mL IL-2 for 48 hours. (B) Incubation of cells with IL-2 at concentrations of 100, 500, and 1000 IU/mL significantly reduced the migration of these cells (at 100 ng/mL) toward CXCL12. Index of migration indicates the fold increase in the number of migrating cells in response to CXCL12 vs control. (C) IL-2–activated CD56⁺ cells show increased percentage of migration in response to CXCL9 and CXCL10, the ligands for CXCR3. (D) Sorted CD3⁺CD16^– NK T cells migrate better, in a dose-dependent manner, in response to CXCL12 than do CD16⁺ NK cells. (E) A marked reduction in the migration toward CXCL12 after activation with IL-2 is shown for the sorted NK and NK T cells. (F) The migration of CD56⁺ cells toward CXCL12 can be completely inhibited by incubating the cells with pertussis toxin (PTX) or neutralizing anti-CXCR4 antibodies. The results represent the average of at least 3 independent experiments ± SE. *P < .05.