FIG. 2.

LGT virus NS3 protein induces apoptosis. (A) Expression of NS3 in Vero cells results in cleavage of cellular DNA. Vero cells transfected with empty vector or plasmid expressing NS3 were fixed 18 h after transfection and processed for TUNEL assay. TUNEL-positive cells were visualized by fluorescence microscopy (magnification, ×200). (B) NS3 expression results in loss of viable cells. Vero and Neuro-2a cells were cotransfected with plasmids expressing β-galactosidase and NS3, Casp8-HA, or the empty vector. Cells were fixed and stained with X-Gal (5-bromo-4-chloro-3-indolyl-β-d-galactopyranoside), and the number of viable, blue-stained flat cells was determined at 24, 48, and 72 h after transfection relative to vector-transfected cells at the same times, set at 100%.