Cre/loxP-based reversible immortalization of human hepatocytes

An ideal alternative to the primary human hepatocytes for hepatocyte transp lantation would be to use a clonal. cell line that grows economically in cu lture and exhibits the characteristics of differentiated, nontransformed he patocytes following transplantation. The purpose of the present studies was to establish a reversibly immortalized human hepatocyte cell line. Human h epatocytes were immortalized with a retroviral vector SSR#69 expressing sim ian virus 40 large T antigen (SV40Tag) gene flanked by a pair of loxP recom bination targets. One of the resulting clones, NKNT-3, showed morphological characteristics of liver parenchymal cells and expressed the genes of diff erentiated liver functions. NKNT-3 cells offered unlimited availability. Af ter an adenoviral delivery of Cre recombinase and subsequent differential s election, efficient removal of SV40Tag from NKNT-3 cells was performed. Her e we represent that elimination of the retrovirally transferred SV40Tag gen e can be excised by adenovirus-mediated site-specific recombination.