Open AccessAbsence of Toll-Like Receptor 4 Explains Endotoxin Hyporesponsiveness in Human Intestinal Epithelium
Author(s) -
Sandhia Naik,
Eric J. Kelly,
Lisa Meijer,
Sven Pettersson,
Ian R. Sanderson
Publication year - 2001
Publication title -
journal of pediatric gastroenterology and nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.206
H-Index - 131
eISSN - 1536-4801
pISSN - 0277-2116
DOI - 10.1097/00005176-200104000-00011
Subject(s) - tlr4 , toll like receptor , tlr2 , peripheral blood mononuclear cell , microbiology and biotechnology , receptor , lipopolysaccharide , transfection , intestinal epithelium , messenger rna , biology , epithelium , medicine , cell culture , immunology , innate immune system , in vitro , biochemistry , gene , genetics
The Toll protein in Drosophila regulates dorsal ventral patterning during embryogenesis, and participates in antibacterial and antifungal host defense. Mammalian homologues are termed Toll-like receptors and, to date, nine have been cloned (TLRI-9) in humans. They are characterized by extracellular leucine-rich repeats and a cytoplasmic domain similar to the interleukin 1 receptor. Both TLR2 and TLR4 recognize various bacterial cell wall components including lipopolysaccharide (LPS). This results in the activation of the NFkappaB pathway. Peripheral blood mononuclear cells (PBMCs) express both TLR2 and TLR4. The authors hypothesized that the expression of TLR 2 and TLR4 in human intestinal epithelial cells differs from PBMCs because of the abundance of LPS in the intestinal lumen.