Figure 1

PRRSV Nsp2 activates NF-κB.

(A) HeLa cells were co-transfected with the NF-κB-Luc reporter plasmid (0.2 μg), pRL-TK plasmid (0.05 μg), along with 0.6 μg of the indicated expression plasmid encoding PRRSV nonstructural protein. Selected cells were stimulated by 20 ng/ml TNF-α at 30 h post-transfection, and whole-cell extracts were prepared for the dual-luciferase activity at 6 h after this treatment. **P < 0.01 as compared with vector control. (B) An increasing quantities of indicated Nsp2 expression plasmid (0, 0.1, 0.2, 0.4, 0.8 μg) was co-transfected with pNF-κB-Luc and pRL-TK into HeLa cells. Cells were harvested at 36 h after transfection and analysed for luciferase activity. (a) P < 0.05 compared with the vector group, (b) P < 0.05 compared with 0.1 μg Nsp2 protein transfection group, (c) P < 0.05 compared with 0.2 μg Nsp2 protein transfection group, (d) P < 0.05 compared with 0.4 μg Nsp2 protein transfection group. Values for the samples were normalized using Renilla luciferase values and expressed as relative fold change in NF-κB-regulated gene expression compared with vector group, and each untreated empty vector control value was set as a basis level of 1. Data represent means of three replicates and results are representative of at least three independent experiments.