title: Gastric mucosal recognition of Helicobacter pylori is independent of Toll-like receptor 4.
abstract: Little is known about the interactions between Helicobacter pylori, which specializes in colonizing the mucin layer that covers the gastric mucosa, and primary gastric epithelial cells. The expression pattern of Toll-like receptors (TLRs) in primary gastric epithelial cells and cell lines was compared. Primary cells did not express TLR4, whereas all cell lines expressed a nonsignaling form of TLR4. Because other cells within the mucosa expressed TLR4, it was next investigated whether H. pylori can be recognized by TLR4--they cannot. Moreover, H. pylori infection of primary cells induced a regulated production of interleukin (IL)-6, IL-8, and tumor necrosis factor-alpha, whereas infection of cell lines only resulted in IL-8 production. The cytokine production in all cell types was strictly cag dependent. These findings indicate that, although the epithelium is important in directing the immune response against H. pylori infections, the response is independent of TLR4.
authors.affiliation: Microbiology and Tumor Biology Center, Karolinska Institutet, S-171 77 Stockholm, Sweden. Fredrik.Backhed@mtc.ki.se
authors.forename: Fredrik
authors.initials: F
authors.lastname: Bäckhed
authors.forename: Bachra
authors.initials: B
authors.lastname: Rokbi
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Torstensson
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhao
authors.forename: Christina
authors.initials: C
authors.lastname: Nilsson
authors.forename: Delphine
authors.initials: D
authors.lastname: Seguin
authors.forename: Staffan
authors.initials: S
authors.lastname: Normark
authors.forename: Alison M J
authors.initials: AM
authors.lastname: Buchan
authors.forename: Agneta
authors.initials: A
authors.lastname: Richter-Dahlfors
mesh_terms: D000293:Adolescent; D000328:Adult; D001706:Biopsy; D002478:Cells, Cultured; D029721:Drosophila Proteins; D004847:Epithelial Cells / Q000276:immunology / Q000382:microbiology; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology*; D016480:Helicobacter pylori / Q000472:pathogenicity*; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008875:Middle Aged; D011706:Pyloric Antrum / Q000166:cytology / Q000276:immunology / Q000382:microbiology; D011956:Receptors, Cell Surface / Q000378:metabolism*; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D014407:Tumor Cells, Cultured
chemical_list: D029721:Drosophila Proteins; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors