Expression patterns of porcine Toll-like receptors family set of genes (TLR1-10) in gut-associated lymphoid tissues alter with age.

The aim was to study the expression pattern of the porcine TLR family (TLR1-10) genes in gut-associated lymphoid tissues (GALT) of varying ages. A total of nine clinically healthy pigs of three ages group (1 day, 2 months and 5 months old) were selected for this experiment (three pigs in each group). Tissues from intestinal mucosa in stomach, duodenum, jejunum and ileum and mesenteric lymph node (MLN) were used. mRNA expression of TLRs (1-10) was detectable in all tissues and TLR3 showed the highest mRNA abundance among TLRs. TLR3 expression in stomach, and TLR1 and TLR6 expression in MLN were higher in adult than newborn pigs. The western blot results of TLR2, 3 and 9 in some cases, did not coincide with the mRNA expression results. The protein localization of TLR2, 3 and 9 showed that TLR expressing cells were abundant in the lamina propria, Peyer's patches in intestine, and around and within the lymphoid follicles in the MLN. This expressions study sheds the first light on the expression patterns of all TLR genes in GALT at different ages of pigs.