TSLPR CAR demonstrates activity comparable with CD19 CAR. (A) Schematic diagram of second-generation CD19 and the CD22 CAR constructs. Both CARs have identical transmembrane and signaling domains to the TSLPR CAR. (B) Flow cytometric surface expression of protein L on TSLPR, CD19, and CD22 CAR T cells at 5 days postviral transduction, demonstrating efficacy of CAR transduction. (C) TSLPR, CD19, and CD22 CAR-redirected T cells were injected IV into NSG mice (3 × 106/mouse) previously engrafted with the patient xenograft cell line JH331-LUC 29 days earlier and followed by bioluminescent imaging. T cells transduced with GFP were used as a negative control. ACT, adoptive cell transfer; D, day. (D) JH331-LUC–bearing NSG mice were treated as in Figure 6C but including a group receiving a log lower dose of CAR T cell. Control mice received 3 × 106 GD2-targeted CAR T cells.
