Figure 2. Prominent peribronchiolar lymphocytic inflammation, epithelium-infiltrating CD3+ cells, and epithelial dysplasia in allogeneic HCT mice exposed to poly I:C (Allo+poly I:C).
Lungs were inflated and preserved two-weeks following poly I:C exposure. Representative sections photographed at 400x magnification are shown. H&E staining demonstrated minimal peribronchiolar cellular inflammation in both (A) unexposed syngeneic (Syn+control) and (B) unexposed allogeneic (Allo+control) lungs. Small, mononuclear cells in the peribronchiolar region were visible in sections from both (C) Syn+poly I:C and (D&E) Allo+poly I:C lungs, with more prominent cellular inflammation in Allo+poly I:C samples. (F) Additional immunohistochemistry revealed these peribronchiolar cells to be CD3-positive. Only Allo+poly I:C animals demonstrated epithelium-infiltrating CD3+ cells (black arrows) and epithelial dysplasia with several superimposed disorganized epithelial cell layers (white arrows) on both (E) H&E-stained and (F) CD3-stained sections. (G&H) Further digital enlargement of E&F (inset boxes) are representative images of infiltrating CD3+ cells (black arrows) and epithelial dysplasia (white arrows) seen throughout Allo+poly I:C lung tissue.