Effects of swine gut antimicrobial peptides on the intestinal mucosal immunity in specific-pathogen-free chickens.

Sixty specific-pathogen-free chickens were randomly divided into 2 groups (30 chickens for each group) to determine the effect of swine gut antimicrobial peptides (SGAMP) on intestinal mucosal immunity. All chickens were raised in negative-pressure isolators and fed the same diet. The results were as follows. (1) In the SGAMP group, the number of mast cells was increased markedly in the duodenum from d 21 to 49 (P < 0.05), and similar results were observed in the jejunum and ileum after being treated with SGAMP (P < 0.05). However, fewer mast cells were observed in those same tissues in the control. (2) Intraepithelial lymphocytes in the duodenum, jejunum, and ileum were increased significantly from d 21 to 49 in the SGAMP group compared with the control (P < 0.05). (3) Compared with the control, goblet cells were increased significantly in duodenum and jejunum from d 35 to 49 (P < 0.05) after SGAMP treatment and in the ileum were increased from d 21 to 49 (P < 0.05). (4) Swine gut antimicrobial peptides upgrade the expression of secretory IgA at different sites within the intestinal tract. The results strongly support that SGAMP can enhance the intestinal mucosal immune parameters of specific-pathogen-free chickens. Our research contributes to the further understanding of immunoregulatory mechanisms of intestinal mucosal immunity and the contribution of SGAMP to this process.