Figure 6.

T lymphocytes carrying CAR46/28ζ expand and persist in vivo after antigenic stimulation. Activated CD3⁺ lymphocytes expressing either CAR46ζ or CAR46/28ζ and double transduced to express eGFP-FLuc gene (5 × 10⁶ cells) were injected intraperitoneally into SCID mice bearing either κ⁺ Daudi cells or λ⁺ SP53 cells (5 × 10⁶ cells) labeled with RLuc gene. No exogenous cytokines were injected into the mice. Survival and expansion of transgenic T cells were monitored using an in vivo imaging system (Xenogen-IVIS Imaging System). Panel A illustrates that the persistence and intensity of the signal measured as maximum photon/sec/cm²/sr (p/s/cm²/sr) was less in mice receiving CAR46ζ⁺ T cells (top panels) than in mice given CAR46/28ζ⁺ T cells (bottom panels). Panel B illustrates the mean ± SD of 4 mice per group (P < .001). This panel also shows that CAR46/28ζ⁺ T cells did not expand/survive in mice bearing the κ^–/λ⁺ SP53 tumor cell line (broken line).