Analysis of the CCR7 surface expression on CD56^dull NK cells upon interaction with either immature or mature DCs. (A-B) Freshly isolated NK cells were purified and cocultured for 1 hour with immature DCs (iDCs) or mature dendritic cells (mDCs) in the absence or in the presence of anti–HLA I mAbs or in the presence of anti–HLA I mAbs plus neutralizing anti–IL-18 mAb (A middle and bottom lines) and assessed for CCR7 expression. Control cultures were performed with exogenous IL-18 for 18 hours to verify the efficiency of the neutralizing anti–IL-18 mAb (A top line). The values reported in the top right corners indicate the percentage of CD56⁺ CCR7⁺ NK cells. (B) NK cells that had acquired the CCR7⁺ phenotype after 1-hour coculture with mDCs, in the presence of anti–HLA-class I mAb, were analyzed for KIR expression using a mixture of anti-KIR mAbs. The values reported in the top left and in the top right corners indicate the percentage of CD56⁺ KIR⁻ and of CD56⁺ KIR⁺ NK cells, respectively. Data are representative of 10 independent experiments performed using different donors.