Regulation and Molecular Mechanism of on Resistance to F18 in Weaned Piglets.

Toll-like receptor 5 (TLR5) plays an important role in immune system. In this study, we performed transcriptome analysis of the duodenum in F18-resistant and -sensitive Sutai weaned piglets and analyzed the differential expression of . The cellular localization of TLR5 was investigated, and the effect of expression on invasion was evaluated after pig small intestinal epithelial cell lines (IPEC-J2) were stimulated by . The results showed that TLR5 expression level in duodenum and jejunum were significantly higher in F18-sensitive than in F18-resistant piglets. TLR5 protein was mainly expressed in the cytoplasm and cell membrane. The expression of genes associated with the TLR5 signaling pathway were significantly higher in -overexpressed cells than in control cells. Bacterial adhesion was higher in -overexpressed cells than in blank cells and lower in interference than in blank cells. The core promoter region of included two CpG islands and 16 acting elements. The methylation of the mC-6 site in the second CpG island of the promoter region had a regulatory effect on expression. Therefore, plays an important regulatory role on invasion. Low expression of inhibited the immune response and decreased cell damage, which was conducive to the resistance to stimulation. In conclusion, this study preliminarily revealed the molecular mechanism of gene regulating the resistance of piglets to , and provided a new candidate gene for screening resistance markers in pigs.