Hepatic dendritic cells: immunobiology and role in liver transplantation

Traditional investigations of hepatic dendritic cells (DC) have focused on immunohistochemical studies of these cells within normal and pathological l iver tissue. The recent availability of reagents for the improved character ization of DC, together with cytokine-based methods for the expansion of li ver DC both in vivo and in vitro have begun to protide new insight into tbe immunobiology of these important antigen-presenting cells. Hepatic DC prob ably play a key role in the host response to blood-borne pathogens, and in tbe pathogenesis of infectious and autoimmune liver diseases. They appear t o be important in determining the balance between liver transplant toleranc e and rejection. Their possible role iu oral and portal venous tolerance re mains to be defined, In this article, we focus on emerging aspects of hepat ic DC immunobiology, with particular reference to liver transplantation.