Fig. 2

Retroviral transduction and functionality of NK cells. a Top and middle: Schematic representation of retroviral vectors containing human CXCR2 and NGFR, respectively, and representative histograms of the transgene expression on non-transduced (NT), CXCR2- and NGFR-transduced primary NK cells. Bottom: Flow cytometry analysis of CXCR2 and NGFR expression on NK cells after the transduction (n = 24). Horizontal bars represent the mean transduction efficiency. b NK cell-mediated cytotoxicity against K562 cells after 5 h. One of four representative experiments is shown. NK cell-mediated cytotoxicity against (c) ACHN and (d) Caki-2 cells after 20 h. One of five and three representative experiments is shown, respectively. e Flow cytometry analysis of NK cell degranulation after stimulation with K562 at a E:T ratio of 1:1 (n = 4) and with ACHN and Caki-2 at a E:T ratio of 2:1 to 1:1 (n = 3 for each cell line). f Flow cytometry analysis of NK cell IFN-γ production after stimulation with K562. Data in e and f are depicted as mean ± SEM of fold-change compared with non-transduced NK cells and analyzed with repeated measures one-way ANOVA. g Proliferation of non-transduced (NT), NGFR-transduced, and CXCR2-transduced NK cells after 7 days as assessed by CFSE staining. Results are representative of three experiments