The Role Of Intestine Iron Transport System In Bacterial Infection Of Intestinal Epithelial Cell

One of the important lines of defense against microoganism infection is the withholding of nutrients to prevent microoganism growth in a process termed nutritional immunity. Previous studies have demonstrated that the most important forms of nutritional immunity is the sequestration of the metal ions, including iron, manganese and zinc. Iron is one of the most important trace elements in living organisms. Dietary iron absortion and transport mainly get through duodenal enterocytes. Intestine is important infection site for pathogenic microoganisms. DMT1, Ftn and Fpnl are involved in absorption, cellular storage, and release of iron, respectively, which are composed of mammalian intestinal epithelia cell iron transport system. In intestinal epithelial cells, it remains unclear that the role of DMT 1, Ftn and Fpnl in the pathogenic bacterial infection. In the study, we mainly investigated whether intestinal iron transport system plays an important role in bacterial infection of human intestinal epithelial cells. Our study demonstrated that knockdown of the genes related to intestinal iron transport system led to reduce resistance of the Caco-2 cells to pathogenic bacterium Salmonella typhimurium, indicating that intestinal iron transport system palys a crucial role in S. typhimurium infection. Meanwhile,we have founded that intracellular bacteria S. typhimurium infection upregulated the expression of DMT1、 Ftn and Fpnl. In contrast, extracellular bacterium Pseudomonas aeruginosa PA 14 infection did not induced expression of DMT 1, Ftn and Fpnl. In conclusion, our study demonstrated that mammalian intestinal iron transport system is important for resistance to bacterial infection.