Expression of VAChT and 5-HT in Ulcerative colitis dendritic cells.

Ulcerative colitis is a chronic inflammatory condition of the gastrointestinal tract that can affect people of worldwide. In contrast with Crohn's disease, that can relate the entire thickness of the bowel wall, the inflammation of ulcerative colitis is limited to the colonic mucosa. Immune cells including activated T cells, plasma cells, mast cells, macrophages, and dendritic cells (DCs) trigger the inflammation. Furthermore, dendritic cells are antigen presenting cells involved in maintaining intestinal immune homeostasis. It has been described an increment of number in DCs colonic mucosa of patients with ulcerative colitis. The immune cells such as antigen-presenting cells can act as autocrine or paracrine modulators. Recent studies showed that dendritic cells synthetized and released classical neurotransmitters as glutamate, dopamine, acetylcholine, and serotonin. Paraformaldehyde-fixed intestinal tissues, obtained from the stricture sites of ten patients with ulcerative colitis were analyzed by immunostaining for Langerin/CD207, serotonin and vesicular acetylcholine transporter. As controls, unaffected (normal) portions of five patients were also investigated. Aim of this study was to characterize for the first time the human gut dendritic cells of ulcerative colitis patients, with Langerin/CD207 that is a c-type lectin expressed by different types of DCs and to colocalize in the same cells the expression of serotonin and vesicular acetylcholine transporter, showing the link between dendritic cells, gut enterochromaffin cells or autonomic nerves in immune activation and generation of intestinal inflammation.