Fig 2.

All donor NK products killed KIR-ligand mismatched MM cells. Donor NK cells lysed MM cell targets lacking inhibitory KIR-ligands including patient MM cells (when available), with the exception of donor 7, who did not have allo-reactive NK cells. K562, patient MM cells, U266 MM cell line (homozygous C group 1 and HLA-Bw4 negative), and patient PHA blasts were employed as targets in a standard 4-h ⁵¹Cr release assay, at E/T ratios of <10:1. Patient primary MM cells were available for patients 2, 3, 6, 7 and 8. Specific lysis percentage was calculated as (test release − spontaneous release)/(maximal release − spontaneous release) × 100. All experiments were performed in triplicate wells and the mean ± SD were presented. One of three independent experiments was shown. All experiments were performed with the final NK cell product, which had been incubated overnight (products 1–4) or during cell processing with 300 IU/ml of IL-2 (products 5–10).