CD14.

The GPI-anchored 55 kDa glycoprotein CD14 is expressed on monocytes/macrophages and to a lesser extent on granulocytes. Engagement of CD14 by ligands like lipopolysaccharide, intact bacteria or apoptotic cells can result in either pro- or anti-inflammatory responses. Since the CD14 molecule does not have a membrane spanning domain it cannot transmit a signal into the cell. Some as yet unidentified accessory protein is thought to be involved. It will be important to clarify the signalling systems involved since they may provide a therapeutic target for sepsis intervention strategies.