A, T cells were transfected with empty vector or with 0.5, 1 and 2 µg of CREM α expression vector. After 24h post-transfection Western blot was performed with antibodies against CREM α or β-actin. B, T cells were transfected with different concentrations of CREM α expression vector or with an empty vector. SYK mRNA level was detected by quantitative PCR. Relative mRNA expression normalized to 36B4 is shown as mean ± SEM from one of 3 independent experiments. C, T cells were transfected with different concentrations of CREM α expression vector or with an empty vector. After 24h incubation total SYK protein or β-actin were detected by Western blot and represented as mean ± SEM of densitometry scan of 5 different blots. D, T cells were transfected with different concentrations of CREM α expression vector or with an empty vector. The transfected cells were treated with 1 µg anti-CD3/anti-CD28 antibodies and the levels of phosphorylated SYK and β-actin were measured by Western blot. The data presented as mean ± SEM of densitometry scan of 5 independent blots.