Figure 8
Differential IFN-γ productivity after Cap protein PCV2 vaccination. Comparison of two representative samples of PCV2-vaccinated pigs characterized by higher (A) and lower (B) PCV2-specific IFN-γ productivity per cell, that is larger and smaller spot sizes depending on the amount of IFN-γ secreted by ex vivo PCV2-stimulated cells. The responses shown were observed at 2 weeks after PCV2 vaccination (PV) upon re-stimulation with a PCV2b strain (0.25 MOI). A representative transient increase of IFN-γ productivity per cell is shown in a PCV2-vaccinated pig at 2 weeks (C) and 3 weeks (D) PV. The numbers are relative to the spots counted in the stimulated well shown (2 × 105 PBMC) and (in brackets) the mean of the corresponding unstimulated negative control wells (2 × 105 PBMC). The spot size and spot intensity distributions are shown as histogram plots on a linear scale. PCV2-vac pigs were vaccinated at 3 weeks of age using a PCV2a Cap protein-based subunit vaccine.