Figure 5 from Preclinical Evaluation of Folate Receptor-α Chimeric Antigen Receptor T Cells Exhibits Highly Efficient Antitumor Activity against Osteosarcoma

FH FOLR1-CART antitumor activity against patient-derived osteosarcoma cell lines in vitro. A, FOLR1 expression detected by flow cytometry by a panel of patient-derived osteosarcoma cell lines OS186, OS9, OS525, OS766, OS742, OS33, and OS457. Red, tumor stained with PE-labeled anti-FOLR1; unfilled, isotype control. B and C, FH FOLR1-CAR T cell–induced tumor cell lysis detected by flow cytometry after co-culture at 24 hours at E:T ratios of 1:1 (B) and 10:1 (C) in FOLR1-positive patient-derived osteosarcoma cell lines OS186, OS525, OS766, and OS742. No tumor killing was seen in the FOLR1-negative cell line OS457. D, Cytokines released by FH FOLR1-CART vs. NT T cells co-cultured with patient-derived osteosarcoma cell lines. Concentration (pg/mL) of secreted IL-2, IFN-γ, and TNFα detected in co-culture supernatant following 24 hours of 1:1 T cell-to-tumor cell ratio. *, P < 0.05.