T-plastin surexpression in Jurkat cells favors migration that was reversed by T-plastin down-regulation by siRNA transient transfection. (A) Migration of T-plastin–positive (pcDNA3.1/PLS3⁺, gray) and –negative (pcDNA3.1, white) Jurkat clones was assessed as in Figure 5A. Results are expressed as mean (± SEM) ratio of migration of pcDNA3.1/PLS3⁺ clones (n = 6) and pcDNA3.1 clones (n = 6) relative to migration into medium alone of respective clones, taken as 1. *P < .05, comparison of cell migration toward chemokines to respective cell migration in control medium. (B) Same assay as in panel A using stable T-plastin– expressing Jurkat clones (PLS3⁺ clones) transiently transfected with 200nM control siRNA (white) or PLS3 siRNA (gray). Results are expressed as mean (± SD) ratio of chemokine-induced migration of PLS3 siRNA transfected clones (n = 3) to respective chemokine-induced migration of control siRNA clones (n = 3) taken as 1. **P < .01, ***P < .001, comparison of chemokine-induced cell migration of PLS3 siRNA-transfected PLS3⁺ clones to that of PLS3 clones transfected with control siRNA. In frame is presented the protein expression of T-plastin in 1 representative stable PLS3⁺ Jurkat clones transiently transfected with control siRNA (sicont) or PLS3 siRNA (siPLS3), assessed by Western blotting and normalized by β-actin.