Figure 5

pDC are resistant to PRRSV infection and can prevent infection of MoDC. (A) Nucleocapsid expression in CD172a^lowCD4⁺ pDC and CD172a^highCD4^- monocytes at 24, 48 and 72 h post infection with LV (black line histogram), 2982 (dotted line) or 3267 (dashed line) at an MOI of 2.5 TCID₅₀/cell. Mock-treated cell fluorescence is shown as grey filled histograms. PAM infected with LV (MOI of 1 TCID₅₀/cell) was used as positive control (upper panel). (B) IFN-α levels measured in the cultures shown in A. Bars represent means of triplicate cultures ± 1 standard deviation. A representative example from three independent experiments is shown. (C) Detection of PRRSV nucleocapsid in MoDC cultured alone or with enriched pDC at 24 and 48 h post infection with LV. One million MoDC co-cultured with one millions of enriched pDC or two millions MoDC alone were exposed to LV at an MOI of 1 TCID₅₀/cell. Histograms were obtained from forward/side scatter gated MoDC treated with mock control (tinted line) or LV (black line). (D) Time course of IFN-α secretion in co-cultures of MoDC and pDC shown in panel C. One representative experiment out of two is shown.