Fig. 3

Recognition of human TNBC cells by NKG2D CAR T cells in vitro. a NKG2D CAR-modified T cells secrete IFN-γ during overnight co-culture with NKG2DL-expressing TNBC cells, but not NKG2DL-negative AE17 mesothelioma cells. Mean IFN-γ concentration ± SD (pg/ml) from triplicate cultures is shown. b Lysis of NKG2DL-expressing TNBC cells (MDA-MB-231 fluc) by NKG2D CAR T cells in an 18-h bioluminescence assay at the indicated effector-to-target (E/T) ratios. Untransduced (UNT) CD3+ human T cells and AE17 mesothelioma cells served as negative effector and target cell controls, respectively. c Normalized cell index(CI) plot for target cells (AE17, BT549, MDA-MB-436, and MDA-MB-468) incubated with UNT or NKG2D CAR T cells at different E:T ratios for 24 h. When seeded alone, target cells adhere to the plate and proliferate, increasing the CI readout (red lines). When T cells added to target cells, NKG2CD CAR T cells cause cell cytolysis and subsequent progressive decrease in CI. Y-axis is the normalized CI generated by the RTCA software and displayed in real time. X-axis is the time of cell culture and treatment time in hour. Mean values of the CI were plotted ± standard deviation. d The cell index plot is converted to a % Lysis plot by the xCELLigence Immunotherapy Software