CAR T cell serial killing of adjacent tumor cells in the bone marrow. C57BL/6 mice were sublethally irradiated and injected with Eμ-myc-DEVD tumor cells 7 d before treating them with GFP+ CAR T cells. Mice were subjected to intravital bone marrow imaging 40 h after CAR T cell transfer. Live tumor cells appear in gray, apoptotic tumor cells in blue, and T cells in green. The inset highlights a CAR T cell killing two adjacent tumor cells. Additional squares show examples of CAR T cell-mediated tumor apoptotic events. Scale bar represents 20 μm. Total duration = 64 min.
