Fig. 7. B7H3-GD2 T cells penetrate CNS but do not cause neurotoxicity.

a Schematic of SynNotch receptor with extracellular ligand-binding domain (scFv) directed against B7H3. Upon ligand recognition by the SynNotch receptor, an orthogonal transcription factor is cleaved from the cytoplasmic tail that activates GD2-BBz CAR (101-GD2 which uses GD2E101K scFv). b Time-course kinetics of BFP expression by flow cytometry in B7H3-BFP T cells co-cultured with B7H3⁺ CHLA255 NBL for 3 days. c Kinetics of cytotoxicity of UT and B7H3-GD2 T using live-cell imaging (enumeration of GFP⁺ tumor cells) against CHLA255 NBL cells at indicated E:T ratios. d Bioluminescence images of CHLA255 NBL tumor growth upon i.v. injection into NSG mice (1 × 10⁶ cells/mouse) and treatment 7 days later with i.v. injection of 1 × 10⁷ of UT, B7H3, and B7H3-GD2 T cells. Surviving mice were followed for a minimum of 100 days post-tumor inoculation. e Immunohistochemical analysis of CD3 expression (brown staining) in the brain of mice treated with UT, B7H3, B7H3-GD2, and GD2-B7H3 CAR-T cells. f left: Representative flow cytometry plots from single-cell homogenized brain tissue stained for murine CD45 and CD3, (middle) histogram of CAR-T cells identified among infiltrating CD3⁺ T cells using an anti-Fab antibody. Right: Summary data representing the percentage of T cells in total live single cells in the brain of treated animals. Data shown are representative of three independent experiments (b), mean for minimum of four replicate (c), mean ± SD (b). Two-tailed t test (b, f). n = 5 mice (B7H3-GD2, B7H3) and n = 4 mice (UT). Additional immunohistochemical images are provided in the Supplementary Information. Individual BLI and source data are provided as a Source Data file.