Fig 4.

Antibodies from pigs immunized with soy-mSEB and E. coli-mSEB effectively neutralized native SEB activity in vitro. Sera collected at day 38 postimmunization were used in an in vitro neutralization assay to demonstrate the ability to limit native SEB-induced cytokine responses. Dilutions (1:33 or 1:100) of sera from soy-mSEB-immunized, E. coli-mSEB-immunized, or control animals were mixed with 0.5 μg/ml of native SEB for 30 min prior to the addition of the mixtures to cultures of pig splenic leukocytes. Forty-eight hours after coincubation, culture supernates were taken and porcine IFN-γ secretion determined using an ELISA. Results are presented as mean values (plus SEM) for triplicate determinations for each immunogen group (n = 3 or 4). Asterisks indicate statistically significant differences (P < 0.01) compared to control animals.