Repository of Research and Investigative Information

Repository of Research and Investigative Information

Hormozgan University of Medical Sciences

Inhibition of CEA release from epithelial cells by lipid A of Gram-negative bacteria

(2015) Inhibition of CEA release from epithelial cells by lipid A of Gram-negative bacteria. Cellular and Molecular Biology Letters.

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A number of bacterial species, both pathogenic and non-pathogenic, use the human CEACAM family members as receptors for internalization into epithelial cells. The GPI-linked CEA and CEACAM6 might play a role in the innate immune defense, protecting the colon from microbial invasion. Previous studies showed that CEA is released from epithelial cells by an endogenous GPI-PLD enzyme. GPI-PLD activity was reported to be inhibited by several synthetic and natural forms of lipid A. We hypothesized that CEA engagement by Gram-negative bacteria might attenuate CEA release from epithelial cells and that this might facilitate bacterial colonization. We tested the hypothesis by examining the effect of Escherichia coli on CEA release from colorectal cancer cells in a co-culture experiment. A subconfluent monolayer culture of colorectal cancer cells (LS-180, Caco-2 and HT29/219) was incubated with E. coli. While there was a significant reduction in CEA secretion from LS-180 and HT29/219 cells, we found only a small reduction of CEA shedding from Caco-2 cells compared to the level from the untreated control cells. Furthermore, lipid A treatment of LS-180 cells inhibited CEA release from the cells in a dosedependent manner. Western blot analysis of total lysates showed that CEA expression levels in cells co-cultured with bacteria did not differ from those in untreated control cells. These results suggest that lipid A of Gram-negative bacteria might play a role in preventing the release of CEA from mucosal surfaces and promote mucosal colonization by bacteria. © University of Wrocław, Poland 2015.

Item Type: Article
Additional Information: cited By 0
Keywords: carcinoembryonic antigen; Escherichia coli lipopolysaccharide; glycosylphosphatidylinositol phospholipase D; lipid A; trypan blue; carcinoembryonic antigen; lipid A; phospholipase D, Article; bacterial colonization; CACO 2 cell line; cancer cell culture; cell surface; cell viability; coculture; colorectal cancer; controlled study; enzyme linked immunosorbent assay; epithelium cell; Escherichia coli; HT 29 cell line; human; human cell; immunoblotting; intestine cell; monolayer culture; nonhuman; protein secretion; Western blotting; antagonists and inhibitors; colorectal tumor; dose response; drug effects; epithelium cell; Escherichia coli; host pathogen interaction; metabolism; microbiology; pathology; physiology, Bacteria (microorganisms); Escherichia coli; Negibacteria, Blotting, Western; Caco-2 Cells; Carcinoembryonic Antigen; Colorectal Neoplasms; Dose-Response Relationship, Drug; Epithelial Cells; Escherichia coli; Host-Pathogen Interactions; HT29 Cells; Humans; Lipid A; Phospholipase D
Subjects: QU Biochemistry. Cell Biology and Genetics > QU 300-560 Cell Biology and Genetics
Divisions: Research Vice-Chancellor Department > Food Health Research Center
Depositing User: مهندس هدی فهیم پور

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