9A10 and 6E8 inhibit infection and PRRSV-related NF-κB pathway pre- and post-attachment. For pre-attachment assays, PAMs were pre-incubated with mAbs (100 μg/mL) at 37 °C for 1 h, and inoculated with 100 TCID50 ZJfh17 for 1 h. For post-attachment assays, PAMs were treated with ZJfh17, and then post-incubated with mAbs. After 24 hpi, total RNA was extracted and used as template for qRT-PCR using primers specific for N (A,E), NF-κB (B,F), IL-8 (C,G), and IL-1β (D,H). GAPDH was detected as the internal reference. Experiments were performed in triplicate and data are shown as mean ± SD. Statistical significance is indicated as * (p < 0.05); ** (p < 0.01); **** (p < 0.0001).