Antigen-presenting cell function in the tolerogenic liver environment.

The demands that are imposed on the liver as a result of its function as a metabolic organ that extracts nutrients and clears gut-derived microbial products from the blood are met by a unique microanatomical and immunological environment. The inherent tolerogenicity of the liver and its role in the regulation of innate and adaptive immunity are mediated by parenchymal and non-parenchymal antigen-presenting cells (APCs), cell-autonomous molecular pathways and locally produced factors. Here, we review the central role of liver APCs in the regulation of hepatic immune function and also consider how recent insights may be applied in strategies to target liver tolerance for disease therapy.