Open AccessJournal Article
The monocyte differentiation antigen, CD14, is anchored to the cell membrane by a phosphatidylinositol linkage.
TLDR
It is demonstrated that CD14 is a member of the family of PI-anchored proteins and suggest that soluble forms of CD14 represent molecules that completely lack thePI-anchoring system.Abstract:
CD14 is a myeloid differentiation Ag expressed primarily on peripheral blood monocytes and macrophages. Although its function is unknown, the CD14 gene maps to a region encoding several myeloid growth factors and receptors. Analysis of the CD14 protein sequence deduced from the cDNA shows that although the CD14 protein contains a characteristic leader peptide, it lacks a characteristic transmembrane region, suggesting that CD14 may be anchored to the membrane via glycosylphosphatidylinositol (PI). Treatment of monocytes as well as a CD14-expressing neuroglioma cell line with PI-phospholipase C removed CD14 from the cell surface. Furthermore, monocytes from a patient with paroxysmal nocturnal hemoglobinuria, a disease characterized by lack of expression of other PI-linked proteins, failed to express CD14. Interestingly, the CD14-expressing neuroglioma cell line, which had been transfected with a single CD14 cDNA, released a soluble form of CD14 into the supernatant. Soluble forms of CD14 have previously been observed in serum of normal individuals and in culture supernatants of CD14+ cells. Biosynthetic experiments reveal that this soluble form of CD14 (48 kDa), which is smaller than the form released from the membrane by PI-phospholipase C (53 kDa), does not contain ethanolamine, the first constitutent of the PI-anchoring system. These studies demonstrate that CD14 is a member of the family of PI-anchored proteins and suggest that soluble forms of CD14 represent molecules that completely lack the PI-anchoring system.read more
Citations
More filters
Journal ArticleDOI
Metabolic endotoxemia initiates obesity and insulin resistance
Patrice D. Cani,Jacques Amar,Miguel A. Iglesias,Marjorie Poggi,Claude Knauf,Delphine Bastelica,Audrey M. Neyrinck,Francesca Fava,Kieran Tuohy,Chantal Chabo,Aurélie Waget,Evelyne Delmée,Béatrice Cousin,Thierry Sulpice,Bernard Chamontin,Jean Ferrières,Jean-François Tanti,Glenn R. Gibson,Louis Casteilla,Nathalie M. Delzenne,Marie-Christine Alessi,Rémy Burcelin +21 more
TL;DR: It is concluded that the LPS/CD14 system sets the tone of insulin sensitivity and the onset of diabetes and obesity and lowering plasma LPS concentration could be a potent strategy for the control of metabolic diseases.
Journal ArticleDOI
CD14, a receptor for complexes of lipopolysaccharide (LPS) and LPS binding protein.
TL;DR: CD14, a differentiation antigen of monocytes, was found to bind complexes of LPS and LBP, and blockade of CD14 with monoclonal antibodies prevented synthesis of TNF-alpha by whole blood incubated with LPS.
Journal ArticleDOI
Multipotent mesenchymal stem cells from adult human synovial membrane
TL;DR: It is demonstrated that human multipotent MSCs can be isolated from the SM of knee joints and have the ability to proliferate extensively in culture, and they maintain their multilineage differentiation potential in vitro, establishing their progenitor cell nature.
Journal ArticleDOI
Receptor-Dependent Mechanisms of Cell Stimulation by Bacterial Endotoxin
TL;DR: How LBP enables LPS binding to CD14 and how complexes of LPS and soluble or GPI-anchored CD14 participate in cell activation are discussed, and the evidence supporting a model for a functional LPS receptor of myeloid cells, which is multimeric, is reviewed.
Journal ArticleDOI
Signal transduction by the lipopolysaccharide receptor, Toll-like receptor-4
TL;DR: This review is intended to sum up the present understanding of the events following LPS binding to TLR4, and to create a model of the signalling pathways activated by LPS.