CD14 mediates endotoxin induction of nitric oxide synthase in cultured brain glial cells

Here we show that lipopolysaccharide (LPS) induction of glial inducible nitric oxide synthase (iNOS) requires membrane (m) and soluble (s) forms of CD14. In glial cell cultures, an anti-rat CD14 monoclonal antibody detected CD14 protein in whole cells and cell lysates, and reduced LPS-dependent iNOS expression. Glial cells and normal brain tissue expressed CD14 mRNA, as revealed by isolation of a rat CD14 clone (rCD14) from an astrocyte cDNA library, and RT-PCR analysis. Finally, serum reduced the ED(50) of LPS required for glial iNOS expression, and antibodies against sCD14 blocked the potentiating effect of serum.