Combination of IDO inhibitor and CD19-CART therapy on IDO-positive tumors. (A) Schematic representation of the experiments in SCID/Beige mice comparing the antitumor effect of IDO inhibitor (1-MT), CD19-CARTs, or the combination of both on IDO-positive malignancies (Raji-IDO and Jeko-1). (B) Time course of Raji-IDO tumor bioluminescence. Data represent mean ± SD of 7 mice per group from 2 independent experiments (*P < .05). (C) Time course of Jeko-1 tumor bioluminescence. Data represent mean ± SD of 8 mice per group from 2 independent experiments (*P < .05). (D) CD19-CARTs retained similar cytotoxic activity against Raji-control and Raji-IDO in a 4-hour ⁵¹Cr-release assay. (E) Luciferase-labeled CD19-CARTs were injected intravenously in mice that had been subcutaneously inoculated with nonlabeled Raji-control (left flank) and Raji-IDO (right flank). The time course of T-cell bioluminescence at Raji-control and Raji-IDO tumor site is shown. Data represent mean ± SD of 4 mice.