Preferential uptake of ODN C by KIR3DL2⁺ cells. The uptake of FITC–ODN C by KIR3DL2⁺ or KIR3DL2⁻ NK cell populations sorted from IL2-activated NK cell populations (A) or KIR3DL2⁺ or KIR3DL2⁻ NK cell clones (B; derived from the same donor) was analyzed by flow cytometry after 2 hours of treatment with 5 μg/mL FITC–ODN C. In panel A, the percentage of ODN C–FITC⁺ cells is indicated in the right quadrants. In panel B, treatment with dextran sulfate was used as a negative control (dot profiles). (C) The uptake of FITC–ODN C (full black profiles) was analyzed on KIR3DL2-transfected HEK-293T cells (right) and untransfected control (left) after 1 hour of treatment with 1.2 μg/mL FITC–ODN C. Treatment with dextran sulfate was used as a negative control (empty profiles). Mean fluorescence intensities (MFIs) are reported. (D) HEK-293T cells transfected with plasmid coding for KIR3DL2 full-length receptor (left) or for its cytoplasmic truncated form (KIR3DL2Δ, right panel) were treated or not for 18 hours with the indicated doses of ODN C, and then KIR3DL2 expression was assessed by cytofluorimetric analysis. Results shown in each panel are representative of 3 distinct experiments.