Regulation of cytokines by Nbs-pFc with or without PRRSV infection. PAM were innoculated with or without GD-HD (MOI of 0.01) for 1 h then treated with 30 μM of Nb6-pFc, Nb53-pFc and TAT-Nb53, and collected at 24 and 36 hpi. Relative mRNA levels of PRRSV ORF7, IL-1β, IL-6, IL-8, IL-10, IL-12p40, IFN-α, IFN-β, and TNF-α were assessed using quantitative real-time qRT-PCR. Values were normalized to the internal GAPDH control. Data are representative of three independent experiments performed in triplicate and are shown as the mean ± SD. P values were calculated using ANOVA as < 0.05 (*), < 0.01 (**), and < 0.001 (***) compared with cells infected with PRRSV alone (ns: not significant).