Selective retention of activated CD8(+) T cells by the normal liver

Activation-induced cell death resulting in peripheral deletion of CD8(+) T cells is associated with the accumulation of large numbers of apoptotic T c ells in the liver. The hypothesis that this accumulation results from the i ntrahepatic trapping of T cells from the circulating pool predicts that the liver should retain T cells, which subsequently undergo apoptosis, Here we test this prediction, Perfusion of the liver with lymphocyte mixtures show ed retention of activated, but neither resting nor apoptosing, T cells, Thi s trapping was selective for CD8(+) cells and was mediated primarily by ICA M-1 constitutively expressed on sinusoidal endothelial cells and Kupffer ce lls, T cells trapped in the liver became apoptotic, The normal liver is the refore a "sink" for activated T cells.