FIG. 1.

Effect of VacA on IL-2 secretion by Jurkat and LBRM-33 T cell lines. Jurkat cells (A) or LBRM-33 (B) cells were pretreated with medium alone, acidified buffer, several different types of acid-activated VacA (10 μg/ml), or cyclosporine and then stimulated with PMA-ionomycin. After 24 h, the cells were pelleted, and the supernatants were analyzed in a human or mouse IL-2 ELISA. Results represent the means ± standard deviations of triplicate determinations and are representative of three independent experiments. ***, P ≤ 0.001; **, P ≤ 0.01 (compared to acidified buffer). No Stim., no stimulation.