Chemotactic activity of pML cells in response to various chemokines. (A) Chemotactic activity of pML cells in response to chemokines SDF-1α, MIP-3α, TARC, SLC, RANTES, and CTACK. Migration efficiency of pML cells was estimated using a Transwell assay in the presence of various concentrations (2, 20, and 200 ng/mL) of chemokines. The number of migrating pML cells was counted using a hemocytometer viewed under a microscope. The results are expressed as the fold number of the untreated control pML cells. The number below each bar corresponds to each chemokine: 1, control; 2, TARC; 3, LARC; 4, RANTES; 5, CTACK; 6, SLC; and 7, SDF-1α. These results were confirmed by 3 independent experiments. The data are presented as mean values ± SD. *P < .05. **P < .01. (B) Chemotactic activity of pML cells and normal T cells. The number of migrating cells was measured as described for panel B in the presence of 0, 2, 20, and 200 ng/mL SDF-1α. The results are expressed as the fold number of the normal T cells. These results were confirmed by 3 independent experiments. The data are presented as mean values ± SD. *P < .05; **P < .01.