Bidirectional transendothelial migration of monocytes across hepatic sinusoidal endothelium shapes monocyte differentiation and regulates the balance between immunity and tolerance in liver.

Unlabelled: Monocytes are versatile cells that can fulfill proinflammatory and anti-inflammatory functions when recruited to the liver. Recruited monocytes differentiate into tissue macrophages and dendritic cells, which sample antigens and migrate to lymph nodes to elicit T-cell responses. The signals that determine monocyte differentiation and the role of hepatic sinusoidal endothelial cells (HSECs) in this process are poorly understood.

CMV infection of human sinusoidal endothelium regulates hepatic T cell recruitment and activation.

Background & Aims: Human cytomegalovirus infection (HCMV) is associated with an increased morbidity after liver transplantation, by facilitating allograft rejection and accelerating underlying hepatic inflammation. We hypothesized that human hepatic sinusoidal endothelial cells infected with HCMV possess the capacity to modulate allogeneic T cell recruitment and activation, thereby providing a plausible mechanism of how HCMV infection is able to enhance hepatic immune activation.

Methods: Human hepatic sinusoidal endothelial cells were isolated from explanted livers and infected with recombinant endotheliotropic HCMV.