Fig. 5

GD2-specific CAR-T cells kill retinoblastoma cells in vitro without causing antigen loss in WERI-Rb1. a IFNG and IL2 release of CAR-T cells following a 24-h co-culture at a 2:1 E:T ratio with retinoblastoma cell lines (mean ± SD, n = 3). Cell surface expression of activation markers CD137 and CD25 (b) and inhibitory receptors LAG3, PD1 and TIM3 (c) on CAR-T cells is shown upon a 24-h co-culture at a 2:1 E:T ratio (mean ± SD, n = 3). Color-coding is the same as used in a. d Cytotoxicity of GD2-specific CAR-T cells is displayed in comparison to mock-transduced T cells. Cytotoxicity was measured by a luciferase-based killing assay following a 24, 48 and 72 h co-culture at a 2:1 E:T ratio (mean ± SD, n = 3). Color-coding is the same as used in a. e Cell line-dependent loss of GD2 cell surface expression is shown after a 72-h co-culture as well as day 10 and 14 after CAR-T cell removal (n = 3). *, p ≤ 0.5; **, p ≤ 0.01