Fig. (5) Lck is required for gp120 inhibition of SDF-1α induced chemotaxis. (A) Purified primary human CD4 T cells were treated with either gp120 (IIIB) (1µg/ml) or (B) SDF-1α and analyzed for cofilin phosphorylation over time by immunoblotting with anti-phospho- S3cofilin. (C) Primary human CD4 T cells were pre-treated with Lck inhibitor PP2 (2μM) for two hours and then treated with gp120 (IIIB) (1µg/ml) and analyzed for cofilin phosphorylation over time. (D) Cells were pre-treated with either gp120 (IIIB) or BSA (1µg/ml) for 2 min and then chemotactic response to SDF-1α (40nM) in the presence or absence of the Lck inhibitor PP2 was measured in transwell chemotaxis chambers. P values were determined by Student’s paired t test. (E) J.CaM T cells and J.CaM T cells stably expressing wild-type Lck were pre-treated with either gp120 (IIIB) (1µg/ml) or BSA (1µg/ml) for 2 min and then chemotactic response to SDF-1α (40nM) was measured in transwell chemotaxis chambers for 1 hour. Expression of Lck was confirmed by immunoblotting. P values were determined by Student’s paired t test.