The Expression Of IL-22 In The Early Stage Of Murine TNBS Colitis

Objective:Interleukin (IL)-22 plays an important role in intestinal mucosal immune. IL-22 increases the innate immunity of Intestinal epithelial cells and protects mucosal tissues from damage. IL-22 expression was detected in the inflamed intestine. Here, IL-22 expression in the early stage of murine TNBS-induced colitis and the character of IL-22~+ cell subsets in the mesenteric lymph nodes in colitis was investigated to provide the data for clarifying the effect of IL-22 on colitis.Methods:2.5%TNBS mixed with ethanol was used to induce murine colitis. The method of weight measurement, observation of colon gross anatomy and histological evaluation of colitis was used to prove the effectiveness of model.After 24 hours, IL-22 and IL-22BP mRNA expression in different parts of colitis including ulcers, adjacent tissues and relatively normal colon were determined by RT-PCR and IL-22 protein levels were determined by immunohistochemistry in each group. The proportion of IL-22~+ cell subsets in the mesenteric lymph nodes and peyer's patchs were analyzed using flow cytometry. Results:1. Murine TNBS-induced colitis was successfully established.2. IL-22 expression in the early stage of murine TNBS colitis The IL-22 mRNA expression in the early stage of murine TNBS colitis was increased, and IL-22BP mRNA was decreased. In contrast to the normol colonic mucosa IL-22-expressing cells were increased and localized mainly in ulcers.3. The character of IL-22~+ cell subsets in the mesenteric lymph nodes Massive IL-22 expression was detected in colitis mice model in the mesenteric lymph nodes, the proportion of CD3-IL-22~+ cells increased more than CD3~+IL-22~+ cells. Compared with the CD3-NK1.1hi cells , CD3-NK1.1int NK cells had higher expression of IL-22 in the mesenteric lymph nodes.Conclusions:IL-22 and IL-22~+ innate immune cells play important role in the early stage of colitis.