FIG 5.
Effects of selection I mutations on viral replication in the absence of the K188-del mutation. (A) IFA of naive BHK-21 cells transfected with WT or mutant (G100VprM, P179SNS2A, and A373VNS3) genome-length RNA. Viral E protein expression (green) was detected using MAb 4G2. (B) Plaque morphology. The culture fluids harvested from the transfected cells from panel A on day 5 p.t. were subjected to plaque assay using BHK-21 cells. (C) Viral titers on day 5 from the transfected cells from panel A. (D) IFA of NS2A-expressing BHK-21 cells transfected with the WT or mutant genome-length RNA. E protein expression (red) was detected using MAb 4G2. (E) Plaque morphology. The culture fluids harvested on day 5 p.t. from cells in panel D were used to perform a plaque assay on BHK-21 cells. (F) Viral titers on day 5 p.t. from the transfected cells in panel D. Means ± standard deviations from three independent experiments are presented.