NCR^dullAML-NK cell killing of normal monocyte-derived DCs. The expression of NKp30 was analyzed by flow cytometry on NK cells obtained from 3 healthy donors (NCR^bright[A]) or 7 AML patients (1 of 2 patients with NCR^bright phenotype [B], or 1 of 5 patients with NCR^dull phenotype [C]) as described in “Study design.” Black histograms represent the isotype-matched negative controls; and white histograms, the PE-conjugated anti-NKp30 mAb staining. On the corresponding diagrams, the 3 different NK cells (ie, normal NCR^bright NK, NCR^bright AML-NK, and NCR^dull AML-NK) were assessed for cytolytic activity against the P815 murine cell line (column i), immature Mo-DCs (iDC, column ii), and mature Mo-DCs (mDC, column iii). ▪ represent the redirected killing with the IgG1 anti-CD16 mAb; •, the redirected killing with the IgG1 anti-NKp30 mAb; and ♦, the redirected killing with an irrelevant IgG1 mAb. ▵ represent NK cells against iDCs, and the crosses represent the natural killing of NK cells against iDCs blocked with an IgM anti-NKp30 mAb. Grey circles represent the natural killing of NK cells against mDCs, and ○ represent the blocking of HLA class I engagement by IgM anti-HLA class I mAb. These data are from 1 experiment of 5 representative and independent performed. Error bars indicate ± standard deviation (SD).