Fig. 3

Effects of GSNO on PCV2 replication in PK-15 cells. When monolayers reached about 80% in each well of 24-well cell culture plates, the cells were incubated with 125 μM GSNO or 125 μM GSNO plus Hb (5, 10, 20 μM) for 6 h, with four wells for each treatment, then the cells were infected with PCV2 (1 MOI) in the presence of various drugs for another 72 h. Non-treated cells served as the mock, and the infected cells without drug treatment were considered as the PCV2-infected control. PCV2-positive cells were detected by IFA (a), and the appearance of infected cells was judged by FITC staining intensity. The culture supernatant from each well was collected for determination of NO production (b), in addition, the cells in each sample were also gathered for assay of the percentage of infected cells (c), virus titers (d), and viral DNA copies (e). Relative infected cells (%) = number of PCV2-positive cells from experimental samples / number of PCV2-positive cells from PCV2-infected control × 100. Data were presented as means ± SD from three independent experiments. *P < 0.05, **P < 0.01 vs PCV2-infected control