IFN-γ Secretion by Resting NK Cells Is Induced by Soluble Antibodies to KIR2DL4

<div><p>(A) KIR2DL4 expression on the surface of NK cells immediately after isolation (day 0) or after 7, 14, or 21 d in culture with autologous feeder cells and rIL-2. Cells were stained with mAb 33.</p> <p>(B) Resting NK cells were incubated with soluble (10 μg/ml), plate-coated (5 μg/0.1 ml/well), or bead-bound (4 beads/cell) antibodies to KIR2DL4 (mAb 33) or CD16 (mAb 3G8). After 24 h, culture supernatants were tested by ELISA for IFN-γ production.</p>