Fig 4. Effect of Campylobacter jejuni challenge on immune gene expression in cecal tonsils at (a) 0 dpi and (c) 1 dpi, and spleen at (b) 0 dpi and (d) 1 dpi.

On d14 of age, birds were weight-matched and randomly assigned to two treatments: control and challenge. Birds were orally challenged with 0.5 mL of 2.4 x 10⁸ CFU/mL of Campylobacter jejuni or mock-challenged with 0.5 mL of 0.85% saline. Transcript levels of genes were determined by real-time RT-qPCR. Results were expressed as the mean + SEM fold change in tissue mRNA levels in the challenge treatment as compared to the mock-challenged control treatment. *P < 0.05; **P < 0.01 compared with control (n = 6), Student’s t-test.