PRRSV specific IFN-γ
T lymphocyte subsets in the blood of pigs. PBMC isolated from individual pigs at 26 dpv (A–C) and 14 dpc (D–F) were unstimulated (control) or stimulated with PRRSV (virus) or pooled five conserved peptides (peptides). Cells were immunostained for T cell surface markers CD3ε, CD4α, CD8α, and δ chain (γδ T cells) and intracellular IFN-γ+ cells are shown. Each bar represents the average cell counts of 50 000 events from 4 or 5 pigs ± SEM. Lowercase alphabet and asterisks indicate a statistically significant difference (a or *P < 0.05, **P < 0.01 and c or ***P < 0.001) between control (PBS) and vaccine received groups under the same ex vivo stimulation condition, or between different stimulation conditions within the same treatment group.