Figure 8.

Hinge truncation results in similar progressively diminished EGFR-specific sdCAR response to human glioblastoma xenografts in vivo. (A) NSG mice were injected (N= 5 mice/group) subcutaneously with 1×10⁶ U87vIII cells stably expressing mKate2. At 7 and 14 days post-tumor challenge mice were injected intratumorally with 1×10⁷ total T cells (approx. 2.5×10⁶ hinge-modified sdCAR-T cells) or with untransduced control T cells (mock). Tumor growth was monitored via caliper measurements. N=5 mice per group. (B) Mice were sacrificed at pre-determined endpoints based on animal condition or tumor volume >2000 mm³. P values are derived from Mantel-Cox test of survival curves in comparison with untreated mice. (C) In vivo imaging was performed to examine the mKate2 fluorescent signal associated with tumor cells. (D) Blood was drawn from challenged mice and examined for the proportion of sdCAR-transduced cells (GFP+) within the hCD45+ lymphocyte fraction at the final timepoint where all experimental mice were alive (day 21). (E) sdCAR-T cells, or total hCD45+ cells for mock T cell treated mice, were examined for differentiation status using antibody staining for human CCR7 and CD45RA. See inset for gating strategy used to delineate effector, naïve/SCM, central memory, or effector memory-RA+ (EMRA) cells.