GÉTICA 2021

58 VII FORO DE I nmunología Traslacional e INMUNOTERAPIA DEL CÁNCER Figure 4 (cont.). In vivo anti-tumor efficacy of STAb-T19 cells. NSG mice (n = 6/group) received 1 × 106 NALM6Luc cells (iv) followed 2 days after by a single iv injection of 5 × 106 NT-T, CAR-T19 (5 × 105 19-BBζ+) or STAb-T19 (5 × 105 19-BiTE+) cells. Tumor progression was moni- tored weekly by bioluminescence imaging, PB was obtained at days 19 and 39 (sacrifice), and tissue samples were obtained after sacrifice. (h-k) Patient-derived xenograft murine model: NSG mice received 1 × 106 primary human CD19+ CD22+ CD10+ B-ALL blasts (iv) followed 3 weeks after by a single iv injection of 5 × 106 NT-T (n = 4), CAR-T19 (5 × 105 19-BBζ+) (n = 8) or STAb-T19 (5 × 105 19-BiTE+) (n = 8) cells. Leukemia progression was monitored bi-weekly by bleeding and subsequent analysis of blast percentage in PB; additionally, BM samples were obtained on day 28 after T cell infusion and BM and spleen samples were obtained after sacrifice. (h) Timeline of experimental design. (i) Representative dot plots showing human B-ALL (CD3-CD19+) and human T (CD3+CD19-) cell populations in PB, and BM of mice treated with NT-T, CAR-T19 or STAB-T19 cells, 28 and 56 days after T cell infusion. (j) Percentage of leukemic cells in PB (day 0 toward day 56), spleen (at sacrifice) and BM (days 0, 28 and 56). (k) Human T cell persistence over time in PB, spleen and BM at the indicated time points. Data are shown as mean ± SD; each dot represents an independent mouse. Significance was calculated by an unpaired Student t test.