XXXX 's milk protein induced changes in the expression of HLA-DR antigens on colonic epithelial cells.

@entity1 @entity32 @entity379 @entity291
BACKGROUND: Normal colonic epithelial cells do not express HLA-DR antigens unless they become inflamed. It is possible that colonic epithelial cells may function as antigen-presenting cells once HLA-DR is induced by @entity32 . OBJECTIVE: The aim of this study was to investigate whether @entity291 's milk protein (CMP) is capable of inducing changes in HLA-DR expression on colonic epithelial cells, providing indirect evidence that CMP may activate cell-mediated immune mechanisms within intestinal mucosa. METHODS: HLA-DR expression was evaluated by flow cytometry on cultured @entity1 colonic epithelial cell line (HT-29) before and after treatment with bacterial lipopolysaccharide (LPS) or recombinant @entity379 ). Untreated and LPS- or @entity379 -treated HT-29 cells were then cultured in the presence of CMP. The changes in epithelial HLA-DR expression induced by CMP on untreated and LPS- or @entity379 -treated HT-29 cells were examined. RESULTS: Untreated HT-29 cells expressed very little HLA-DR molecule. Bacterial LPS or @entity379 induced a significant HLA-DR expression on HT-29 cells. When untreated HT-29 cells were cultured in the presence of CMP, there was little induction of HLA-DR expression. Culture of LPS- or @entity379 -treated HT-29 cells in the presence of CMP induced a significant increase in HLA-DR expression, which was much greater than on HT-29 cells treated with bacterial LPS or @entity379 only. CONCLUSIONS: Our results suggest that CMP initiates an immune response in the intestinal mucosa and may be responsible for the activation of cell-mediated immunity after enteric @entity32 .
