FIG. 2.
Induction of ROS (A) and nitrite ions (B) in cultured neutrophils removed from F98- or 1326/28Φr-inoculated pigs or following in vitro rechallenge (R) with F98 (MOI, 10). Neutrophils taken from pigs were also protected by 1326/28Φr inoculation prior to challenge with F98 (bars labeled with both 1326/28 and F98); these neutrophils were also reinfected (R) or not reinfected. +ve, neutrophils isolated from uninfected pigs cocultured with 1 μg/ml zymosan (A) or 1 μg/ml phorbol myristate acetate (B); −ve, neutrophils removed from uninfected pigs. Solid bars, 2 h postinfection; shaded bars, 7 h postinfection; hollow bars, 24 h postinfection. Each experiment was replicated three times on six separate occasions (18 pigs per group). An asterisk indicates a significant increase (P < 0.05) compared with uninfected control levels.