Figure 4: STAg-induced proliferative responses of spleen cells. Isolated spleen cells from T. gondii-infected (25 days p.i.) WT or AhR-/- mice were stimulated with 2.5 g/mL of STAg for 5 days in vitro. 3[H]TdrU was added (0.5 Ci/well) 20 hours before harvesting, and counts per minute (cpm) were calculated using a liquid scintillation counter (a). Secretion of IL-2 (b), IL-12 (c), and IFN-γ (d) in supernatants recovered from cell cultures were evaluated by an ELISA-sandwich. Means + SE, Student’s t-test.