A VISION OF CELL-DEATH - INSIGHTS INTO IMMUNE PRIVILEGE

Immune privilege is a term applied to several organs that have a uniqu e relationship with the immune response. These sites prohibit the spre ad of inflammation since even minor episodes can threaten organ integr ity and function. The most prominent examples of these are the eye, br ain and reproductive organs where immune responses either do not proce ed, or proceed in a manner different from other areas. Once thought to be a passive process relying on physical barriers, immune privilege c an now be viewed as an active process that utilizes multiple mechanism s to maintain organ function. Recently there has been a renewed intere st in immune privilege when it was shown that two privileged sites (th e eye and testes) constitutively express FasL, which functions by kill ing lymphoid cells that invade these areas. Here we will examine the r ole of Fast in immune privilege and discuss how this molecule interact s with other elements of the inflammatory response to maintain organ i ntegrity in the face of potentially damaging immune reactions.