A critical role of TRAIL expressed on cotransplanted hepatic stellate cells in prevention of islet allograft rejection.

Hepatic stellate cells (HSCs) have demonstrated a strong T-cell inhibitory activity. In a mouse islet transplantation model, cotransplanted HSCs can protect islet allografts from rejection. The involved mechanism is not fully understood. We showed in this study that expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), an important apoptosis-inducing ligand, on HSCs was crucial in protection of islet allografts, since HSCs derived from TRAIL knockout mice demonstrated less inhibitory activity towards T-cell proliferative responses, and substantially lost their capacity in protecting cotransplanted islet allografts from rejection, suggesting that TRAIL-mediated T cell apoptotic death is important in HSC-delivered immune regulation activity. 2009 Wiley-Liss, Inc. Microsurgery 2010.