FIG. 4.

Analysis of VacA effects on IL-2 signaling. Preactivated CD4⁺ T cells (7 days post-CD3/CD28 activation) were removed from IL-2 and treated with the indicated additives for 8 h. Cells were then stimulated with IL-2 for 5 min (A and right panel of D) or for 20 min (B and C). Alternatively (left panel of D), cells were pretreated with the indicated additives and then TCR/CD28 activated and cultured for 2 days prior to harvesting. Cells were then lysed, and samples were immunoblotted with indicated antibodies as described in Materials and Methods. Reactivity with phosphorylated (P) or total (T) proteins is indicated. Results are representative of three independent experiments.