FIG. 5.

mTOR and eIF4E phosphorylation requires ERK1/2, JNK, and Akt activation in T lymphocytes. (A and B) Isolated CD4⁺ T lymphocytes were mock treated (DMSO) or treated with the MEK1/2 inhibitor UO126 (UO), the JNK inhibitor SP600125 (SP), the p38 kinase inhibitor SB203580 (SB), or the PI3K inhibitor LY294002 (LY) 1 h prior to activation with anti-CD3/CD28 for 0 to 2 days. Cell lysates (30 μg) were resolved by SDS-page followed by immunoblotting with antibody specific for mTOR phosphorylation (A) or eIF4E phosphorylation as well as total eIF4E protein (B). The mTOR phosphorylation level in panel A was quantified and normalized to β-actin levels using the Scion Image 4.0 software program.