Fig. 5.

Relative expression of cytokine transcripts (IFN-γ, IL-12p40, IL-13, and IL-6) by spleen mononuclear cells after culture for 24 h with medium only, UV-inactivated NDV, or UV-inactivated Vaxxitek. Chicks received 1 × 10⁷ CFU/chick of either L. acidophilus, L. reuteri, L. salivarius, or an equal combination (total of 1 × 10⁷ CFU/chick) of all three bacteria (mix) or PBS (control group) by oral gavage weekly starting on the day of hatch and throughout the trial. Spleens were isolated from chickens immunized with live NDV and Vaxxitek vaccines at 2 weeks of age. Data are expressed as the relative expression of cytokine mRNA levels normalized to the expression of β-actin. *, treatment significantly different (P < 0.05) from the corresponding unstimulated medium control. Error bars represent standard errors of the means, and different letters indicate that the treatments are significantly different from the other treatments within the group.