FIG 2.

CO produced by HO-1 catalysis mediates the inhibitory effect of HO-1 on PRRSV replication. MARC-145 cells were pretreated with the CO scavenger Hb (50 μg/ml) for 1 h, and after being washed with PBS three times, the cells were infected with PRRSV at an MOI of 0.1. One hour later, the virus solution was discarded and the cells were treated with 80 μM CoPP in the presence or absence of 50 μg/ml Hb. At 24 hpi, PRRSV ORF7 mRNA (A), N protein (B), extracellular viral RNA (C), and progeny virus production (D) were determined using qPCR, Western blotting, and TCID₅₀ assay. Data are expressed as the means ± SD of the results of three independent experiments. P values were calculated using Student's t test. *, P < 0.05; **, P < 0.01; ***, P < 0.001.