Figure 4

Immunohistochemistry of ED1 stain in brain sections treated with rAAV2/IL12 ( A, B, C, D , n = 4), AAV2/GFP ( E, F , n = 2), or PBS ( G, H , n = 2), accompanied with tumor implantation; and that in the brain section treated with nothing (n = 1). Immunohistochemistry of brain sections was performed for ED1 on the last day of week 3 after tumor implantation. The brain sections were stained with hematoxylin for nuclei and ED1 for activated microglial cells. The 1^st column shows the brain sections pictured before immunostaining; the 2^nd column shows the brain sections pictured after staining; the 3^rd to 6^th columns show pictures taken at four quadrants (black squares in 2^nd column) of the tumor adjacent to the normal tissue in the right hemisphere. ED1-positive cells show dark brown. The scale bars indicate 2 mm in 1^st and 2^nd columns and 100 μm in 3^rd-6^th columns.