FIG. 2.

Effect of VacA on IL-2 secretion by primary murine T cells. Splenocytes or purified murine CD4⁺ T cells from FVB/N mice were pretreated with medium alone, acidified buffer, acid-activated s1m1 VacA (10 μg/ml), or cyclosporine and then stimulated with PMA-ionomycin (A) or anti-CD3/anti-CD28 antibodies (B). After 24 h, the cells were pelleted, and the supernatants were analyzed in a mouse IL-2 ELISA. Results represent the means ± standard deviations of triplicate samples from a single experiment and are representative of three independent experiments. (C). Splenocytes from BALB/c, C57BL/6, or FVB/N mice 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. IL-2 secretion was analyzed as described above. No Stim., no stimulation.