Fig. 1: YT-Indy cells are GZMB/PRF competent but naturally spare K562 cells.
From: A synthetic cytotoxic T cell platform for rapidly prototyping TCR function
a YT-Indy cells were co-incubated with either 721.221 cells or K562 cells, each of which was modified by lentiviral transduction to express GZMB-cleavable ECFP-EYFP FRET-reporter. Co-cultures were assembled at 1:1 effector:target ratios and incubated for the time intervals specified. Parallel T = 0 h (T0) controls were prepared for each co-culture condition to assess baseline FRET-shift signal and measure cell loss in co-cultures due to effector cell activity. b The ratio of cell counts from live, single-cell targets gate in flow cytometry (after holding input cell number, resuspension volume, flow rate, and acquisition time fixed for all samples) between K562.FRET/YT-Indy 12 h co-cultures and T0 controls are shown (n = 3, bar height and error bar represent mean ± standard deviation). c K562 cells modified to express FRET2 reporter (GZMB-cleavable CyPet-YPet fusion protein) were either additionally modified with CD19 protein coding sequence or left as CD19−. YT-Indy cells or YT-Indy modified with an FMC63-41BB-CD3ζ anti-CD19 CAR were each co-incubated with both prepared K562.FRET2 and K562.FRET2.CD19 target lines at 1:1 effector:target ratios for 4 h. Percent FRET-shifted values from four independent replicate experiments are plotted (bar height and error bar represent mean ± standard deviation).
