T-plastin expression in CTCL cells favors migration that was inhibited by FK506 pretreatment. (A) T-plastin–positive (PLS3⁺) PBLs (left) and –negative (PLS3⁻) PBLs (right) from SS patients were plated in the upper chamber of a modified Boyden chamber. The lower chamber contained migration medium alone or supplemented with TARC (10 ng/mL) or IP-10 (50 ng/mL). Results are mean (± SEM, n = 6) migration of PLS3⁺ and PLS3⁻ PBLs toward TARC or IP-10 relative to respective migration into medium alone taken as 1. **P < .01, comparison of PLS3⁺ PBL migration toward chemokines to respective cell migration into medium alone. *P < .05, comparison between relative migration of PLS3⁺ PBLs and PLS3⁻ PBLs toward TARC. (B) T-plastin positive (PLS3⁺) and negative (PLS3⁻) PBLs from CTCL were pretreated by FK506 (10μM) or not for 1 hour before migration was assessed as in panel A. Results are expressed as mean (± SEM, n = 6) ratio of migration of FK506-pretreated PBLs (gray) relative to migration of respective control (non-FK506–pretreated) PBLs (white), taken as 1. **P < .01, ***P < .001, comparison of chemokine-induced migration of FK506-pretreated PBLs with the 1 of respective PBLs non-pretreated by FK506.