Getting to grips with the granulocyte: manipulation of granulocyte behaviour and apoptosis by protein transduction methods.

Human granulocytes clearly play an important role in host defence against invading organisms, however they have also been implicated in the pathogenesis and progression of many chronic inflammatory diseases. In addition, these cells have been paramount in gaining a better understanding of many key-signalling pathways regulating fundamental biological processes. Since granulocytes are terminally differentiated and undergo relatively rapid constitutive apoptosis it has been difficult to manipulate intracellular events by transfection or transduction procedures. It has been shown in recent years that the HIV-TAT protein transduction system can be successfully used in granulocytes to manipulate key signalling mechanisms regulating functional responsiveness and survival. In this paper, we review recent literature highlighting important developments using this system in isolated human granulocytes and in inflammatory process in vivo where these cells play a prominent role.