Abstract
Background: Neonatal piglets are susceptible to intestinal infections . Gut is the body’s major immune structure and the intestinal mucosa, which is composed of intestinal epithelial cells (IELs) and subepithelial natural immune cells, is considered as the primary site for eliciting local immune responses to foreign antigens. This study compared the intestinal immune cells of neonatal and weaned piglets to provide a theoretical and mechanistic basis for preventing intestinal infectious diseases. Results: Histological analyses of weaned piglet intestines showed increased crypt depth, high IEL count, and increased areas of ileal Peyer’s patches. Additionally, the duodenal and ileal villi of weaned piglets were longer than those of neonatal piglets. Expression of claudin-3 protein in weaned piglets was remarkably high as compared with neonatal piglets. The number of CD3 + T cells, goblet cells, and secretory cells was high in the small intestines of weaned piglets in vivo. Contrarily, secretory IgA-positive cell numbers in the jejunum remained unchanged between neonatal and weaned piglets. Gene expression of 12 pattern recognition receptor (PRR) (TLR1–10, MDA5, and RIG-I) was examined in neonatal and weaned piglet small intestine (duodenum, jejunum , and ileum). The pattern of mRNA expression level of most PRR genes in the duodenum and jejunum was inverse of that in the ileum. Compared with weaned piglets, there were significantly fewer intestinal lymphocytes at birth in neonatal pigs. Conclusions: The physical, biochemical, and immune-related components of neonatal and weaned piglet small intestines were investigated to provide preliminary data on the pathogenetic mechanism for future studies.
Utilization of peas in early weaned piglet diets. Influence of the type of cereal
