Thy-1 (CD90)-Positive Hepatic Progenitor Cells, Hepatoctyes, and Non-parenchymal Liver Cells Isolated from Human Livers.

In response to liver injury, hepatic cells, especially hepatocytes, can rapidly proliferate to repair liver damage. Additionally, it was shown that under certain circumstances liver resident cells with progenitor capabilities are involved in liver cell proliferation and differentiation. These hepatic progenitor cells (HPCs), known as oval cells in rodents, are derived from the canals of Hering, which are located in the periportal region of the liver. Regarding to different cell niches, which were defined for human HPCs, several markers have been used to identify these cells such as CD34, c-kit, OV-6, and Thy-1 (CD90). The latter was shown to be expressed on HPCs in human liver tissue with histological signs of regeneration. In this chapter we describe a detailed method for the isolation of Thy-1 positive cells from human resected liver tissue. Based on a procedure for isolating primary human hepatocytes and non-parenchymal cells (NPCs) we expanded this protocol to additional enzymatic dissociation, filtration, and centrifugation steps. This results in a bile duct cell enriched fraction of NPCs from which Thy-1 (CD90) positive cells were purified by Thy-1 positivity selection using MACS technique. Bipotential progenitor cells from human liver resections can be isolated using Thy-1 and was shown to be a suitable tool for the enrichment of liver resident progenitor cells for xenotransplantation.