Elotuzumab Enhances CD16-Independent NK Cell-Mediated Cytotoxicity against Myeloma Cells by Upregulating Several NK Cell-Enhancing Genes

Figure 4

LDH assay for the assessment of the eNK (E, frozen) cell-mediated cytotoxicity pretreated without or with Elo (10 μg/mL and/or 20 μg/mL) against K562, U266, RPMI 8226 (RPMI), and MM.1S target (T) cells: (a) results show the cytotoxicity when D-eNKs were cocultured with K562, U266, and RPMI pretreated without or with Elo (n = 3), (b) D-eNK-mediated cytotoxicity against MM.1S pretreated without or with Elo (E : T ratios of 1 : 1, n = 1; 2.5 : 1 to 10 : 1, n = 3). The percentages of eNKs were 55.4% ± 10.0%, 61.2% ± 7.2%, and 63.7% ± 5.9% for donor no. 1 (D#1), no. 2 (D#2), and no. 3 (D#3), respectively, (c) cytotoxicity of Pt-eNKs against K562, U266, and RPMI 8226. The percentages of eNKs were 44.6%, 68.7%, and 79.0% for patient no. 1 (Pt#1, ▪), no. 2 (Pt#2, ▴), and no. 3 (Pt#3, •), respectively, and (d) Pt-eNK cell-mediated cytotoxicity against MM.1S cells pretreated without or with Elo at different E : T ratios (n = 3). Results are presented as mean ± SD of independent experiments, respectively. and .

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