Cytokine gene expression of chicken macrophages stimulated with Pam3CSK4 (10 µg/µl), LPS from <i>E. coli</i> 026∶B6 (1 µg/µl), class B CpG ODN 1826 (10 µg/µl), and non-CpG ODN (10 µg/µl) at 3, 8 and 18 hours post-treatment.

<p>Gene expression relative to the housekeeping gene β-actin was assessed using quantitative RT-PCR. Gene expression is presented as fold changes relative to the medium control group. Error bars represent standard error of the mean. Gene expression among treatment groups was compared statistically using a two tailed student's t-distribution test. Significant up- regulation (<i>P</i> ≤ 0.05) is indicated by *, while significant down-regulation is indicated by §.