KIR2DL2 affects early and late TCR-mediated signaling events differently. (A) KIR2DL2⁺ T cell clones were stimulated with SEB-coated 721.221 or 721.221/HLA-Cw3 target cells for the indicated time points. Cell lysates were tested for phosphorylated ZAP70, phosphorylated PLC-γ1, and phosphorylated Vav1. (B) KIR2DL2⁺ T-cell clones were stimulated with 1 μg/mL control IgG, 1 μg/mL, anti-CD3 + 1 μg/mL IgG, or 1 μg/mL anti-CD3 + 1 μg/mL anti-KIR2DL2 for the indicated timepoints. The amount of total and phosphorylated ERK1/2 was determined by ELISA. The amount of phosphorylated ERK1/2 relative to the amount of total ERK1/2 is shown as mean of triplicate measurements. Results are representative of 3 experiments. (C) KIR2DL2⁺ T-cell clones were stimulated with SEB-coated 721.221 or 721.221/HLA-Cw3 target cells for 60, 90, and 120 minutes. Cell lysates were tested for phosphorylated PLC-γ1 and phosphorylated Vav1. (D) KIR2DL2⁺ T-cell clones were stimulated as in panel B and the level of ERK1/2 phosphorylation was established as in panel B. Results are shown as mean ± SD of triplicate measurements.