FIG 2.

pAPN promotes PDCoV attachment and entry in a viral-dose-dependent manner. (A to D) HEK293 and HEK293-APN cells were plated into six-well plates, and at 90% confluence, the cells were infected at an MOI of 0.01 (A), an MOI of 0.1 (B), an MOI of 1 (C), or an MOI of 100 (D). The cells were then subjected to attachment and entry assays. At 24 h postinfection, the viral RNA copies were confirmed as the positive infection control. (E to H) IPI-21 cells were plated into 12-well plates, and at 90% confluence, the cells were transfected with siRNA-3 or the scrambled siRNA control. After 24 h, the cells were infected at an MOI of 0.01 (E), an MOI of 0.1 (F), an MOI of 1 (G), or an MOI of 100 (H). The cells were then subjected to attachment and entry assays. At 24 h postinfection, the viral RNA copies were confirmed as the positive infection control. Each experiment was repeated at least three times. Error bars represent SD. *, P < 0.05; NS, not significantly different.