2.6. Immunohistochemistry (IHC) Staining

The tissue sections were subjected to pepsin antigen repair after incubation with 3% hydrogen peroxide at room temperature. Then, the sections were blocked with goat serum. After that, the primary antibody (Ag85B, 1 : 300; CD68, 1 : 200; iNOS, 1 : 800; CD163, 1 : 600; IL-10, 1 : 400; TNF-α, 1 : 600; and IFN-γ, 1 : 50) was added, and samples were incubated at 4°C overnight. After rinsing with saline, the secondary antibody was added and incubated at room temperature for 1 h. The samples were finally developed with DAB chromogen. After counter staining with hematoxylin, the samples were observed under a microscope. IHC staining positive expression area was processed by ImageJ.