Cluster Of Differentiation 14 (CD14)

CD14 exists in two forms. It is either anchored into the membrane by a glycosylphosphatidylinositol tail (mCD14) or it appears in a soluble form (sCD14). Soluble CD14 appears either after shedding of mCD14 (48 KDa) or is directly secreted from intracellular vesicles (56 KDa).CD14 takes its name from its inclusion in the cluster of differentiation group of cell surface marker proteins. CD14 was the first described pattern recognition receptor.CD14 acts as a co-receptor (along with the Toll-like receptor TLR 4 and MD-2) for the detection of bacterial lipopolysaccharide (LPS). CD14 can only bind LPS in the presence of lipopolysaccharide-binding protein (LBP). Although LPS is considered its main ligand CD14 also recognizes other pathogen associated molecular patterns.