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

Figure 5

NK-92MI (E, CD16-independent) cell-mediated cytotoxicity pretreated without or with Elo (10 μg/mL and/or 20 μg/mL) against K562, U266, RPMI 8226, and MM.1S target (T) cells, and their IFN-γ production: (a) LDH assay showing the cytotoxicity of NK-92MI pretreated without or with Elo (37°C, 30 min) against various target cells (E : T ratios of 1 : 1 and 2.5 : 1), (b) FCM analyses of dead target cells (CFSE⁺FVD⁺) at an E : T ratio of 2.5 : 1, when NK-92MI were pretreated without (−) or with Elo (37°C, 1 hr). All target cells were prelabeled with CFSE (2.5 μM) before being washed and recounted, and then incubated with the effector cells, (c) degranulation of NK-92MI was assessed as CD107a⁺CD56⁺ expression on various target cells, when NK-92MI were pretreated without (−) or with Elo (E : T = 1 : 1), using FCM assay, and (d) ELISA-based detection of IFN-γ production after coculture of NK-92MI with target cells without (dotted line) or with (solid line) 10 μg/mL of Elo. Results in (a)–(d) are presented as mean ± SD of four to five independent experiments for every assay. , , and .

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