Figure 4. Tuning anti-FGFR4 CARs for low-density antigens.
Expression of RH30_19 antigen surface expression of FGFR4 and CD19 as assessed by flow cytometry (A) and quantified with QuantiBrite beads (B). Quantification of surface FGFR4 expression of cultured RH30_19 and RD cell lines or RH30_19 cells derived from excised tumors. Both flow analysis (left panel) and quantification (right panel) are shown. C. New CAR structural and signaling formats evaluated: double CD3ζ CAR, and CD28 H/TM CAR. D. Surface expression of RJ154HL CAR (anti-FGFR4 CAR) with indicated new signaling domains assessed by flow cytometry. E. Cytotoxicity of anti-FGFR4 CAR-T cells against the RD-ffLuc RMS cell line after 5 hours of co-culture at indicated E:T ratios. F. Cytokine production by anti-FGFR4 CAR after 20 hours of co-culture with RH30_19 target cells. Average of three wells and SEM are indicated for each new CAR format and control UTD.