Figure 4.

RFP inhibits viral RNA and proteins production in the early stage of infection. (A) Marc-145 cells were treated with RFP and infected with PRRSV at an MOI of 1 for the indicated periods. The levels of viral N and Nsp4 proteins were measured by western blot analysis. (B) Marc-145 cells were infected with PRRSV and treated with RFP, and at 24 hpi, the levels of dsRNA were assessed by immunofluorescence staining. (C) The same as (A), except that immunofluorescence was conducted. (D) Marc-145 cells were treated with either RFP or DMSO and infected with PRRSV at an MOI of 1. At 23.5 hpi, puromycin dihydrochloride (Puro, 10 μg/mL) was added to the medium, and protein samples were collected after an additional 0.5 h of incubation. The level of newly synthesized total proteins in the cells was determined by western blot analysis using the Puromycin antibody (MABE343).