FK506 preferentially potentiates TCR-induced expression of LAT.

Jurkat T cells were incubated for 16 hours at 37°C with RPMI-5% FCS (lane 1), RPMI-5% FCS containing the indicated concentrations of anti-CD3 mAb in the absence (lanes 2-4) or presence (lanes 5-7) of 5 ng/mL of FK506, or with RPMI-5% FCS containing 5 ng/mL of FK506 (lane 8). After incubation, the cells were immediately lysed with boiling 2× SDS-PAGE sample buffer. Proteins in WCL were separated by SDS-PAGE and then transferred to membranes and immunoblotted with the indicated antibody. This experiment was repeated 4 times with similar results.