title: Chemokine receptor 4 (CXCR4) is part of the lipopolysaccharide "sensing apparatus".
abstract: Recognition of bacterial lipopolysaccharide (LPS) by the innate immune system involves at least three receptor molecules: CD14, TLR4 and MD-2. Additional receptor components such as heat shock proteins, chemokine receptor 4 (CXCR4), or CD55 have been suggested to be part of this activation cluster; possibly acting as additional LPS transfer molecules. Our group has previously identified CXCR4 as a component of the "LPS-sensing apparatus". In this study we aimed to elucidate the role that CXCR4 plays in innate immune responses to LPS. Here we demonstrate that CXCR4 transfection results in responsiveness to LPS. Fluorescence correlation spectroscopy experiments further showed that LPS directly interacts with CXCR4. Our data suggest that CXCR4 is not only involved in LPS binding but is also responsible for triggering signalling, especially mitogen-activated protein kinases in response to LPS. Finally, co-clustering of CXCR4 with other LPS receptors seems to be crucial for LPS signalling, thus suggesting that CXCR4 is a functional part of the multimeric LPS "sensing apparatus".
authors: Infection and Immunity Group, School of Life Sciences, University of Sussex, Falmer, Brighton, UK.
authors: Martha
authors: M
authors: Triantafilou
authors: Philipp M
authors: PM
authors: Lepper
authors: Caspar David
authors: CD
authors: Briault
authors: Mohamed Abd Elrahman
authors: MA
authors: Ahmed
authors: Josh M
authors: JM
authors: Dmochowski
authors: Christian
authors: C
authors: Schumann
authors: Kathy
authors: K
authors: Triantafilou
mesh_terms: D015153:Blotting, Western; D002634:Chemotaxis, Leukocyte / Q000276:immunology; D042783:Endothelial Cells / Q000276:immunology / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D008070:Lipopolysaccharides / Q000276:immunology*; D018613:Microscopy, Confocal; D020928:Mitogen-Activated Protein Kinases / Q000276:immunology / Q000378:metabolism; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D019718:Receptors, CXCR4 / Q000276:immunology* / Q000378:metabolism; D015398:Signal Transduction / Q000276:immunology*; D014162:Transfection
chemical_list: D008070:Lipopolysaccharides; D019718:Receptors, CXCR4; D020928:Mitogen-Activated Protein Kinases