The surface properties and antigen-presenting function of hepatic non-parenchymal cells.

Hepatic endothelial cells and Kupffer cells have been isolated after pronase digestion of mouse liver and separated by density-gradient centrifugation on Percoll. The endothelial cells had a central round nucleus with a pale cytoplasm which contained non-specific esterase. They had Fc receptors but no Ia antigen, C3 receptor or phagocytic ability. In contrast, the phagocytic Kupffer cell had an initial rounded appearance and possessed Fc and C3 receptors and Ia antigens. Kupffer cells were capable of functioning as antigen-presenting cells as shown by their ability to reconstitute a secondary in vitro antibody in spleen cell cultures depleted of adherent cells. This function was genetically restricted. There was progressive loss of antigen-presenting function of Kupffer cells as time in culture increased. This appeared to be related to the loss of Ia antigen. Hepatic endothelial cells did not restore the antibody response in macrophage-depleted spleen cell cultures. The experiments show that Kupffer cells can function as antigen-presenting cells in a secondary antibody response in vitro and that this function is not due to the presence of endothelial cells in the isolated sinus lining cells.