ICAM-1 expressed on hepatic stellate cells plays an important role in immune regulation

The authors have demonstrated a strong T-cell inhibitory activity of hepatic stellate cells (HSC), which may participate in the establishment of hepatic tolerance. The underlying mechanism is not completely understood. This study showed that intercellular adhesion molecule 1 (ICAM-1) was constitutively expressed on HSC, and up-regulated upon activation. ICAM-1 knockout mice was used to analyze the role of ICAM-1 expressed on HSC, and showed that deficiency in ICAM-1 expression partially reverses HSC immune inhibitory activity both in vitro and in vivo, but did not significantly affect their capacity to induce T-cell apoptosis.