Inhibition of PTEN expression by vector-based siRNA enhanced SDF-1α–induced chemotaxis of T cells. (A) Western blotting confirmed down-regulation of PTEN expression in siRNA/PTEN-transfected cells. The nontransfected cells and the cells transfected with siRNA/PTEN constructs or mock vectors (stable transfection for 2D6 and 2B4 T-cell lines and transient transfection for primary T cells) were lysed and PTEN protein expression detected by Western blotting as described in “Materials and methods”. The samples were also blotted with anti-ERK1/2 as loading control (bottom panel). The results were representative of 3 independent experiments for T-cell lines and 2 independent experiments for primary T cells. (B-D) CXCR4-mediated chemotaxis of 2D6 T cells (B), 2B4 T cells (C), and primary CD4 T cells (D) was enhanced by inhibition of PTEN expression. The chemotaxis assays were performed as described in “Materials and methods.” The results were representative of 3 independent experiments for T-cell lines and 2 independent experiments for primary T cells. Data shown are means ± SD.