CD14 acts as a receptor for endotoxin (LPS), is expressed strongly on monocy¬tes, macrophages and weekly at surface of neutrophiles. CD14 is anchored to cells by linkage to glycosylphosphatidylinositol (GPI) and functions as a high affinity receptor LPS-LBP (lipopolysaccharide binding protein)-complexes. Furthermore CD14 is present in a soluble form in human serum, urine and other body fluids, acts at physiological concentrations as LPS agonist and has at higher concentrations an antagonizing effect in cell activation. The myeloid differentiation antigen CD14 acts as the major receptor for bacterial LPS. The dominant form of the recombinant wild type CD14 is the 50 kDa protein. This is a His-tagged protein.
