E^rns disables stimulation of pDC by infected cells.

<p>A and B. IFN-α induction in pDC after stimulation with SK-6 or SK-6(E^rns) cells infected with CSFV (A) or VRPΔE^rns (B). C. Lack of inhibitory activity in supernatants (SN) of SK-6(E^rns) cells. Supernatants harvested from SK-6 or SK-6(E^rns) cell cultures were added to co-cultures of enriched pDCs with MOCK- or VRPΔE^rns-infected SK-6 cells at 50% (V/V) D. N^pro has no impact on stimulation of pDC by infected cells. SK-6 or SK-6(E^rns) cells were infected with wild type VRPΔE^rns or VRPΔE^rns with the D₁₃₆N mutation in N^pro (VRPΔE^rns D₁₃₆N) abrogating the functional activity of N^pro in preventing IRF3 and IRF7-mediated IFN type I responses. E and F. E^rns also inhibits the activation of pDC by SK-6 cells infected with TGEV (E) and FMDV (F). SK-6 or SK-6(E^rns) cells were infected with TGEV (MOI of 10 TCID₅₀/cell), or FMDV (MOI of 2.5 TCID₅₀/cell), cultured for 90 min followed by addition of enriched pDC. For A to F, IFN-α in the supernatants was quantified by ELISA after 20 h of co-culture. The mean values of three replicates with standard deviation are shown. In A and B, the results are representative of five independent experiments. In C to F, the data is representative of two independent experiments.