Intracellular staining of bovine Foxp3, IL-10, and human Foxp3. (a) Histograms showing intracellular Foxp3 fluorescence intensity of gated human CD4⁺CD25^high, CD4⁺CD25^low and FACS sorted bovine CD4⁺CD25^high, CD4⁺CD25^low T cells after ICS with anti-human/mouse/rat Foxp3 mAb (150DAlexa 647, unfilled histogram) compared to a murine IgG1k isotype control mAb (MOPC-21Alexa 647, filled histogram). (b) Dotplots representing intracellular staining of IL-10 in bovine PBMC gated for live cells after Con A stimulation + Brefeldin A, stained with intracellular biotinylated anti-bovine IL-10 (IgG1) and StreptavidinPE as a second step and the relevant isotype control biotinylated anti-chicken CD107 (IgG1). (c) Dotplots representing intracellular staining of IL-10 in bovine PBMC gated for live cells after Con A stimulation + Brefeldin A, surface stained with anti-bovine CD21, NKp46, CD3, WC1, CD14 and goat anti-mouseFITC as a second step in combination with intracellular biotinylated anti-bovine IL-10 and StreptavidinPE as a second step.