Fig. 2. MAPK activation by parasite lysate, LPS, and CpG requires host cell Ca²⁺. Macrophages were depleted of Ca²⁺ by pre-treating with normal media (N) or BAPTA-AM (15 µM) in Ca²⁺ free EGTA medium (E/B) then treated with medium (m), STAg (A; 50 µg/ml), LPS (B; 100 ng/ml) or CpG (C; 1 µg/ml) for the times indicated. Whole cell lysates collected at the times indicated were used for immunoblotting with phospho-ERK1/2 and phospho-p38 antibodies. Blots were then stripped and reprobed for total MAPK. Results are representative of three experiments each.