CAR.GD2 NKT cells effectively localize to the tumor site and do not induce GVHD in hu-NSG mice. (A) Tumor xenografts were established after injection of CHLA-255 NB cells under the renal capsule for 3 weeks followed by IV injection of CFSE-labeled parental or G28BBz-transduced NKT or T cells from the same donor. Mice were euthanized after 48 hours, and tumor sections were analyzed by fluorescent microscopy. (B) Multiple random fields of tissue slides were scanned from each tumor, and the absolute numbers of CFSE-labeled cells were counted using the NIS Elements AR3.2 software. Whiskers cover 10 to 90 percentiles. Mean ± SD from 5 to 10 fields per mouse, 5 mice per group from 1 of 2 independent experiments. *P < .05; **P < .01; ***P < .001, 1-way ANOVA with Bonferoni posttest analysis. (C) Animals were euthanized after 4 to 5 weeks of receiving cell therapy. Macroscopic evaluation shows significant swelling and granular transformation of liver in mice treated with CAR.GD2 T cells, whereas CAR.GD2 NKT cells had no effect on liver. (D) Microscopic examination shows lymphocytic infiltrates and necrosis in both liver and lungs of mice treated with CAR.GD2 T cells, whereas mice treated with CAR.GD2 NKT cells have no detectable abnormalities in the same organs. Shown are representative images from 1 of 3 experiments with similar results.