Fig. 7.

A2MC2 induces expression of IFN-stimulated genes in primary porcine pulmonary alveolar macrophages (PAMs). (A) STAT2 and IFI56 detected by Western blotting. PAMs were infected with PRRSV VR-2385, A2MC2, and MLV, and at 12 hpi, treated with or without IFN-α. The cells were harvested at 20 hpi for Western blotting. Cell lysate samples from uninfected PAMs with or without IFN treatment were included as controls. (B) IFN bioassay in CRL2843 cells. Supernatant from A2MC2-infected PAMs was diluted and added to the CRL2843 cells 12 h before NDV-GFP inoculation. The cells were observed 24 h after NDV-GFP inoculation. Treatment of the cells with swine IFN-α at a final concentration of 1000 U/ml was included as a positive control. (C) A2MC2 induces elevation of STAT2 in PAM cells from different piglets. PAMs from three piglets were inoculated with A2MC2 at 0.05 TCID₅₀ per cell, respectively, and incubated for 20 h. Cell lysate samples from IFN-α-treated PAM cells were included as positive controls. Cell lysate samples from non-infected cells were included as negative controls in the Western blot analyses.