Fig. 7: Potentiated IS formation and antitumor effects via CD99 domain-incorporated CAR design.

a Schematic of BBz-CAR and HuTJ-BBz-CAR. b Histogram showing CAR expression on untransduced (UnTD) human T, BBz-CAR-T, or HuTJ-BBz-CAR-T cells. Percentage and mean fluorescence intensity (MFI) values are included. Plots of conjugate formation of UnTD human T, BBz-CAR-T, or HuTJ-BBz-CAR-T cells with Raji tumor cells at different time points of coincubation. In b from left to right, n (fields of coverslips) = 5, 7, and 7. Data are pooled from two independent experiments. c IS formation by CAR-T cells. Z-stacked confocal images of F-actin (red) and microtubules (green), and their colocalization (yellow) in UnTD T, BBz-CAR-T, or HuTJ-BBz-CAR-T cells interacting with CMTMR-labeled Raji cells (blue) after staining with phalloidin and anti-tubulin-α antibody. Arrows indicate polymerized actin enriched near the contact areas (yellow arrows) and the MTOC (green arrows) in T and CAR-T cells. F-actin polarization (Polr) and MTOC translocation (Traslc) are denoted on the image of HuTJ-BBz-CAR-T cells, and plotted (n = 12 conjugates per group). Data represent three independent experiments. d Plots of MFI values of CD69, CD25, and CD44 expressed on UnTD T, BBz-CAR-T, or HuTJ-BBz-CAR-T cells after coculture with Raji cells (n = 4 replicates per group). e In vitro tumor killing assay. Numbers of CAR-T and residual tumor cells were quantified during coculture (n = 3 replicates per group). Data represent two (b, c, e) or three (d) independent experiments. Data b–e are shown as mean ± SEM. Statistical significance was assessed using unpaired two-tailed t-test. Exact p-values are presented in the figure. Source data are provided as a Source Data file.