Distribution of intraepithelial lymphocytes, mast cells, and goblet cells in the intestine of alpaca

Intestinal diseases in ruminants are frequent and susceptible to invasion by exogenous substances, and the intestinal mucosal barrier is the first line of defence of the body's immune defence. At present, the study on the structure of intestinal mucosal immune barrier in alpaca is incomplete. Therefore, the alpaca intestines were studied to show the distribution characteristics of intestinal mucosal barrier structure and cells associated with immune system using histology, histochemistry, and immunohistochemistry. The results showed that the intestinal tract of alpaca was composed of mucosa, submucosa, muscularis, and serosa. Intraepithelial lymphocytes were distributed in mucosal epithelium and glands of the large intestine. Mast cells were distributed in each segment of the intestine, mainly in the intestinal lamina propria, intestinal glands, and duodenal glands around, as well as in the muscularis, and the particles of cytoplasm were obvious. Acidic goblet cells were mainly distributed in the ileal mucosal epithelium and ileal intestinal glands, while sialomucins were mainly expressed in the colon. The cells associated with the immune system in the intestinal mucosa of alpaca play an important role in protecting against foreign microbial invasion and infection, and this result provides a theoretical basis for revealing the occurrence of gastrointestinal diseases in alpaca.