Lymphoproliferation of CD8+ T cells. Splenocytes from Neospora-vaccinated mice were isolated postvaccination. Spleen cells were pooled, and CD8+ T cells were isolated by magnetic bead separation (>95% purity as determined by FACS). The cells were cultured in 96-well plates (105 cells/well) and stimulated with mitogen or antigen plus irradiated feeder cells. At 72 (mitogen) or 96 h (antigen) postincubation DNA synthesis was measured by thymidine incorporation. unst, unstimulated; ConA, stimulated with Con A; Toxo, stimulated with Toxoplasma antigen; Neo, stimulated with Neospora antigen.