The present study investigated the effect of glutamine (Gln) on dextran sulphate sodium (DSS)-induced changes in the expression of small-intestinal intraepithelial lymphocyte (IEL) gamma delta-T cells in mice. Mice were randomly assigned to a normal control (NC) group and two DSS-treated groups. The NC group and one of the DSS-treated groups (DSS-C) were fed a common semi-purified diet, while the other DSS-treated group (DSS-G) was fed an identical diet, except that part of casein was replaced by Gln, which provided 25% of total amino acid nitrogen. After being fed the diets for 10d, mice in the NC group were given distilled water, while the DSS-treated groups were given distilled water containing 2 center dot 5% DSS for 5d. At the end of the experiment, the mice were killed. The small-intestinal IEL gamma delta-T-cell subset was isolated for further analysis. The results indicated that DSS treatment resulted in a lower percentage of small-intestinal IEL gamma delta-T cells and higher mRNA expressions of interferon-gamma, TNF-alpha, IL-17, complement 5a receptor and keratinocyte growth factor in IEL gamma delta-T cells. Gln administration increased the proportion of small-intestinal IEL gamma delta-T cells, and the expression levels of immunomodulatory mediator genes in IEL gamma delta-T cells were lower in the DSS-treated mice. The histological findings indicated that the immunoreactive intensity of the tight junction protein ZO-1 in the small-intestinal mucosa was higher in the DSS-G group than in the DSS-C group. These results indicate that pretreatment with Gln increases the proportion of small-intestinal IEL gamma delta-T cells and down-regulates gamma delta-T-cell-expressed inflammatory mediators, which may consequently ameliorate the severity of DSS-induced small-intestinal epithelial injury.
關聯:
BRITISH JOURNAL OF NUTRITION 卷: 111 期: 6 頁碼: 1032-1039
