Macrophage influence on epithelial cell function

摘要

Intestinal macrophages play an important role during acute and chronic mucosal inflammation. They are able to secrete pro-inflammatory mediators, for example IL-1 and TNF, as well as oxygen radicals. The induction of most of these pro-inflammatory molecules is mediated by the actived transcription factor nuclear factor kappa B (NF-kappa B). Activated NF-kappa B could be demonstrated in macrophages and epithelial cells during mucosal inflammation in situ. The study of macrophage influence on epithelial cell function was hampered by the lack of culture models for both cell types. Recently, a model for the primary culture of human intestinal epithelial cells was established. In addition a method for the isolation and purification of intestinal macrophages was described. With these models co-culture investigations are now possible. The incubation of primary human intestinal epithelial cells (IEC) with the typical macrophage cytokine IL-1 (intestinal fibroblasts and IEC do not secrete IL-1) is followed by an induction of NF-kappa B activation (which has also been observed during inflammation in situ). Activated NF-kappa B induces IL-8 expression and secretion from the IEC which can be prevented by inhibitors of NF-kappa B activation.