TSN inhibits PRRSV replication in PAMs. (A) TSN Cytoxicity in PAMs as examined using a MTT assay as described in the methods. (B–D) PAMs grown in 6-well plates (B) or 96-well plates (C and D) were infected with PRRSV NADC30-like (0.5 MOI) for 2 h at 37 °C and then treated with TSN at various concentrations. At 24 hpi, the samples were subjected to viral titer (B), and IFA (C and D) analyses. Results shown in (C) are the mean percentage values of PRRSV-infected cell ratio in TSN-treated groups compared to the DMSO-treated control (0 μM TSN, set as 100%) from three independent experiments, and (D) is one representative IFA data from (C). (E and F) Cells grown in 6-well plates were infected with PRRSV NADC30-like (0.5 MOI) for 2 h at 37 °C and then cultured in fresh media containing various concentrations of TSN. At the indicated time-points post infection, the samples were subjected to qRT-PCR (E), or Western blotting (F) analysis. Statistical significances are denoted by *p < 0.05, **p < 0.01, and ***p < 0.001.