Telomerase activity in rat liver allografts

Background Telomerase activity in grafts may be involved in the alteration of cellular senescence after transplantation or its relevant immunological events. Methods. At the age of 20 weeks, donor livers harvested from DA (RT1(a)) were orthotopically transplanted into PVG (RTIc) or LEW (RT1(1)) rats. Rats having undergone orthotopic liver transplantation (OLT; DA-PVG) naturally overcome rejection, whereas all OLT (DA-LEW) rats die from acute rejection within 14 days. Telomerase activity in liver allografts was measured at various intervals post OLT. Results. At day 7 when the most severe rejection episode was observed in OLT (DA-LEW) and OLT (DA-PVG), the telomerase activity was significantly higher than in syngeneic OLT (DA-DA) rats, in which no rejection occurred. Telomerase activity in tolerogenic OLT (DA-PVG) livers remained elevated for at least 2 months. Conclusion. These results suggest that telomerase activity in allogeneic OLT livers may reflect regenerating hepatocytes or activation of lymphocytes and/or hematopoietic stem cells, associated with rejection or tolerance.