Fig. 7

Persistence of CAR-T cells in vivo. A Frequency of CAR-T cells in tumors at time of necropsy for each experimental group. B Percent of PD-1 expressing intratumoral hCD45⁺ CAR-T cells. C PD-L1 occupancy by atezolizumab—ligand occupancy by atezolizumab was determined by lack of detection of PD-L1 by a second anti-PD-L1 antibody in the harvested tumors at the time of necropsy. D Correlation between PD-L1 occupancy and cRB-340-1 plus atezolizumab colonization of tumors. E percent of hCD45⁺ CAR-T cells among the mixed tumor population three days after IVS with HER2 beads in the treatment groups with sufficient number of CAR-T cells to perform functional assays as per A. F PD-L1 occupancy ex vivo and after 3 days of IVS with HER2 beads without addition of atezolizumab to the culture. G frequency of tNGFR⁺/Q8⁺ CAR-T cell after IVS with HER2 beads. H Percent of tNGFR⁺/Q8⁺ CAR-T cells ex vivo in the mixed tumor population and three days after IVS with HER2 beads. I percent of HER2-expressing cancer cells ex vivo at the time of necropsy. J tumor composition for every experimental group. Asterisks refer to comparisons between RB-340-1 and other groups displaying significant differences. The complete set of statistical values is presented in Additional file 6: Table S6