The liver is a common end organ for metastases, but the nature of the liver-intrinsic mechanisms that control the presence of metastatic lesions in this organ is unclear. In the Proceedings of the National Academy of Sciences USA, Taniguchi and colleagues use a mouse model of metastasis to investigate whether liver-resident populations of immune cells regulate metastatic disease. They find that within the liver, only Kupffer cells, which are liver-resident macrophages, express the C-type lectin receptor dectin-2 to any appreciable extent. Dectin-2-deficient mice show a much greater burden of liver-metastatic disease. Kupffer cells are able to engulf metastatic cancer cells in a dectin-2-dependent manner, although the ligand on the cancer cells remains unknown. This ability to clear metastatic cancer cells might be unique to Kupffer cells, because it is not exhibited by either alveolar macrophages or bone-marrow-derived macrophages. Kupffer cells, therefore, are important in clearing metastases from the liver.

Proc. Natl. Acad. Sci. USA (21 November 2016) http://dx.doi.org/10.1073/pnas.1617903113