Immunofluorescent Staining: Peripheral blood mononuclear cells were isolated from heparinized porcine blood on Ficoll-Hypaque density gradients and incubated with Mouse anti-Porcine CD3e-Biotin, then detected with Streptavidin-FITC. Lymphocytes were gated using light scatter criteria and analyzed on a FACScan (TM) flow cytometer (BD, San Jose, CA). Amount Used: 0.3 ug/10e6 cells.