Gamma herpesvirus 68 (γHV68) replicates in alveolar epithelial cells (AECs). (A) Wild-type mice were infected with 5 × 104 PFU γHV68 on day 0. On day 7 after infection, frozen sections were prepared, and stained with a rabbit polyclonal antisera against γHV68, or with non-immune rabbit sera as control. The goat anti-rabbit secondary was linked to alkaline phosphatase. Vivid replication of γHV68 is visible in alveolar lining cells (original magnification × 100). Sections shown are representative of four mice examined. (B) AECs were isolated from lungs of Balb/c or TLR-9-/- mice treated with bleomycin plus γHV68 on day 21, and were cultured on fibronectin-coated slides (TiterTek). Sections were stained with antibodies (M30 Cytodeath), and the number of positive cells per high power field (HPF; ×400) were calculated (n = 30 HPF per genotype). (C) AECs were isolated from Balb/c or TLR-9-/- mice and cells were infected in vitro with 0.01 or 0.001 PFU γHV68 for 48 hours. Cell lysates were then analyzed for cleaved caspase 3 by western blotting. Data are from one experiment, representative of two.