Fig. 4
IL-15 armored CAR-T cells expressed with IL-15Ra exhibit enhanced anti-tumor activity and reduced toxicity in vivo. A Schematic diagram of mouse experimental processes. 1 × 106 NALM-6-eGFP cells were injected into NOD-SCID mice intravenously to construct the xenograft mouse model. One days after tumor cell injection, 1 × 107 CAR-T cells (2 × 106 CAR positive cells) were injected into tail vein once a day for 3 days. Tumor development was monitored using IVIS. B, C Quantitative bioluminescence (radiance = photons/cm2/sr) imaging data for all mice are shown. Statistic analysis of quantitative bioluminescence of day 34 is shown. D Overall survival rates of mice with NALM-6-eGFP xenografts are shown. E Livers from CAR-T treated mice were collected to stain hematoxylin and eosin. Yellow arrow shows the numerous of infiltrated neutrophils, the black arrow shows the area of necrotic lesions. Right panel shows the GVHD scores of the livers. F Sera from mice were extracted and the concentrations of human IL-15 were measured using ELISA. Results were analyzed by student’s t-test followed by parametric test or Mann–Whitney test. The survival curve was analyzed using Mantel-Cox test. * p < 0.05; ** p < 0.01; *** p < 0.001; n.s., not significant