Fig. 4. Treatment with acid ceramidase induces AKT activation and some tyrosine phosphorylation in Jurkat cells, but does not alter TCR/CD3-induced cell activation. Jurkat T lymphocytes were treated with acid ceramidase as indicated and the phosphorylation of AKT (A, B) or cellular tyrosine phosphorylation (C) was measured by western blotting. In addition, Jurkat cells were stimulated via the TCR/CD3 complex using 10 mg/ml OKT-3 antibodies in the presence or absence or acid ceramidase. The results show that acid ceramidase induces a phosphorylation/ activation of AKT and a tyrosine phosphorylation of some proteins with an apparent weight of 56, 58 and 70 kDa, but does not alter TCR/CD3-mediated T cell activation.Cells were counted prior to any assay and equal numbers were used in each sample. Shown are representative blots from 3 independent experiments (A, C) and the quantitative analysis (B). Given are the mean ± SD, n=3, *p<0.05, ANOVA.