Figure 3
IFN-γ production by PBMC after in vitro stimulation. PBMC were isolated from calves in 16th week of life, 8 weeks after active immunization with rStxMUT. Animals were grouped according to their vaccination status (VAC+ = rStxMUT-vaccinated; VAC− = placebo control) and the supplementation of vitamin E (VitEH = high supplementation; VitEM = moderate supplementation). PBMC were stimulated with lysates of 5 E. coli strains previously isolated at the farm and positive (stx1 +) or negative (stx −) for stx. ELISA values obtained with cell culture supernatants after 24 h of stimulation are depicted in box plots (5–95% interquartile ranges) as percentages of positive controls (S/P). *Asterisk indicates statistical significance (p < 0.05) using Kruskal–Wallis test.