Fig. 3

Manufacturing CAR-T cells using X-VIVO15 basic medium as T cell selection buffer. Using X-VIVO15 basic medium as the CD3⁺ T cell isolation buffer hampered the CAR-T cells manufacturing, and expansion deficiency was related to CD14⁺ cells. a Microscopic images showed numerous adherent cells with engulfed magnetic beads after 48-h T-cell activation inside the cell culture bag. b CD14 expression in live cells before CD3⁺ T cell selection and after 48-h T cell activation. The percentage of CD3⁺ cells express surface CD25 (c) or CD69 (d) before CD3⁺ T cell selection or after 48-h T cell activation. e Fluctuations of cell diameter values throughout the CAR-T manufacturing process. f Expansion fold of CAR-T cells after retroviral transduction. g This experiment compares the expansion fold on day seven after retroviral transduction and the average expansion fold on day 6 in the phase I clinical trial (6 patients with day six cell-counting data recorded). h CAR expression percentage in CD3⁺ cells at the end of CAR-T manufacture (the day of product filling) between this experiment and the phase I clinical trial (all 26 patients)