FIG. 4.

(A) Differential expression of TLR2, TLR4, TLR15, and IL-1β mRNAs in the cecum of five 2-day-old Salmonella enterica serovar Typhimurium-infected chickens expressed relative to those of five uninfected control chickens. Quantitative real-time PCR analysis was performed with 18S RNA as an internal positive control. TLR2 and TLR15 mRNAs were significantly upregulated, with P values of less than 0.05 (*). Error bars indicate the standard error of the means. (B) Differential expression of TLR2, TLR4, TLR15, and IL-1β mRNAs in chicken embryonic fibroblasts stimulated with heat-killed Salmonella enterica serovar Typhimurium for 6, 24, and 48 h expressed relative to those of unstimulated control cells. The axis on the left indicates the fold induction of the TLRs, while the axis on the right indicates the fold induction of IL-1β. Quantitative real-time PCR analysis was performed with 18S RNA as an internal positive control. Asterisks indicate P values of less than 0.05 (*) and less than 0.01 (**). The data are representative of four independent experiments. Error bars indicate the standard errors of the means.