Regulation Of Mucosal Immune System In Rat Intestinal Epithelial Restitution

The gastrointestinal epithelium plays a vital part as a barrier against luminal acid, proteolytic enzymes, and ingested noxious agents. This barrier function is partly dependent on constant renewal of the epithelium which is comprise of a population of highly dynamic epithelial cells with nearly complete turnover every 24 to 96 hours. The balance of proliferative activity with commitment to differentiation and loss of mature cells from the villus requires exquisite mechanisms to regulate this complex system. Findings over the past decades have shown that the mucosal immune system is distinct from the normal immune system and an increasing evidence has suggested that it plays important roles in the pathogenesis and protection of the gastrointestinal epithelium. To explore the regulating mechanism of the mucosal immune system during the process of the epithelial damage and healing ,we sought a model in which epithelial damage and healing resembles some pathological conditions of unknown etiology found in man, e.g. ulcerative colitis. The model is produced by Nippostrongylus brasiliensis infections in rats. Using the flow cytometry, we found that the CD4/CD8 ratio in interepithelial lymphocytes (IEL) was increased by 2-fold on day 4 and 8 post-infection, whereas no significant changes in the CD4/CD8 ratio was observed in mesenteric...