FIG. 5.

Treatment with the vacuolar H⁺-ATPase inhibitor Bfm A1 inhibits VSV-induced giant cell formation. VSV_IND-infected HECA2 cells (MOI = 2) were treated with different concentrations of Bfm A1 beginning at 3.5 hpi. At 24 hpi, the cells were fixed in methanol and stained with Giemsa stain. Giant cell formation was completely inhibited at 1, 10, and 100 nM Bfm A1 (a, b, and c, respectively). Giant cell formation could be induced in 10 nM Bfm A1-treated cells following a brief exposure to pH 5.5 buffer (d).