Fig 6. Effect of Campylobacter jejuni challenge on immune gene expression in cecal tonsils at (a) 14 dpi and (c) 21 dpi, and spleen at (b) 14 dpi and (d) 21 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 are 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.