Fig. 5

In vivo activity of dbBiTE coated murine T-cells against CEA targets in a CEA transgenic mouse model. a Optical imaging of CEA-Tg mice injected i.p. with mouse carcinoma cell line MC38-CEA-Luc at day 9 post injection. Labels: Controls in green and dbBiTE in red indicate group assignments. Mice without detectable bioluminescence were not used. b Number of tumor nodules in pancreas or intestine region in CEA-Tg mice treated 4x every 3 days with 10 million activated CD3 T cells with or without dbBiTE coating. c Tumor nodules indicated by arrows found in peri-pancreatic location of mouse treated with control T cells. d Flow analysis of digested tumor nodules from animals treated with control T-cells (shown in c). Samples were analyzed for presence of DAPI negative live cells, CD45 positive or CEA positive cells. CD45 cells were further analyzed for presence of CD8 and CD4 markers, and CD11b positive myeloid cells were checked for Ly6G and F4/80 markers. e Tumor nodules in peri-intestine location (arrows) of mouse treated with dbBiTE coated T cells. f Flow analysis of tumor nodules (shown in e) using the same staining and gating as in panel (d). Note: tumor nodules were in the range of 2-3 mm diameter determined at the time of necropsy. Due to tumor location and skin color of the mice, bioluminescence measurements were only used to assign mice to groups at the onset of the study