Figure 3

IDO-blockade drives vascular activation after chemotherapy and tumor necrosis after chemo-radiation therapy. A, GL261 tumors were grown in WT host mice treated with TMZ (100 mg/kg, i.p.) and with or without IDO-blockade using 1MT (4 mg/mL in drinking water). Tumors were harvested 5 days after chemotherapy (18 days after implantation) and frozen for immunohistochemical analysis of vascular cell adhesion molecule-1 (VCAM-1, red) on endothelial cells (CD31, green). Nuclei were counterstained with Hoechst (blue). Representative photomicrographs are shown of at least 3 mice per group, from at least 3 independent experiments. Original magnification, ×400; Scale bars, 25 μm. B, GL261 tumors were grown in WT host mice treated with TMZ (100 mg/kg, i.p.) + RT (500 cGy) and with or without 1MT (4 mg/mL in drinking water). Tumors were harvested in formalin 5 days after chemotherapy and stained with hematoxylin and eosin for assessment of tissue architecture. Call-out panel highlights an area of local tumor necrosis. Data are representative of at least 3 mice per group, from at least 3 independent experiments. Original magnification, ×200 (upper panels) and ×400 (lower call-out panel); Scale bars, 25 μm.