Fig. 5

TRAIL-R/SHP-1 inhibits proximal TCR signaling and T cell activation via dephosphorylation of Lck. a, b Immunoprecipitation with anti-TRAIL-R (a) or anti-Lck (b) Ab and then immunoblotting with p-SHP-1 and SHP-1 in murine splenic CD4⁺ T cells treated with TRAIL (10 µg/mL) at indicated time points. Quantification of phosphorylated protein levels are shown at the bottom of the panel. c Immunoprecipitation with anti-TRAIL-R Ab and then immunoblotting with p-Lck (Y394) and Lck in murine splenic CD4⁺ T cells stimulated with anti-CD3 (3 µg/mL) and anti-CD28 (2 µg/mL) Abs in the presence or absence of TRAIL (10 µg/mL) for 30 min. Quantification of phosphorylated protein levels are shown at the bottom of the panel. Data represent analyses from at least three independent experiments; statistical significance determined by two-tailed Student’s t test; NS, no significance; *** p < 0.001. d, e Immunoblotting of Lck in lysates (d) and pooled raft or non-raft fractions (e) of TRAIL-R^WT-FLAG or TRAIL-R^△DD-FLAG T cells stimulated with anti-CD3 (3 µg/mL) and anti-CD28 (2 µg/mL) Abs in the presence or absence of TRAIL (10 µg/mL) for 30 min. Quantification of phosphorylated protein levels are shown at the bottom of the panel