Inhibition of Liver Regeneration in Mice Following Extended Hepatectomy by Transfusion of Lymphokine Activated Killer Cells

Lymphokine activated killer (LAK) cells can destroy not only tumor cells but also syngeneic liver cells. In this study, the effects of passive transfer of LAK cells on liver regeneration were examined by the 3H-thymidine uptake and bromodeoxyuridine (BrdU) labeling methods after resection of 70% of the volume of the liver. LAK cells were infused 12h after hepatectomy and the effects on regeneration of liver cells were examined 36 h later. The transfusion of LAK cells induced significant inhibition of liver regeneration at a dose of 5-10 x 10(7) cells. Neuraminidase treatment of lymphocytes is desirable to enhance the selective entrapment of LAK cells into the liver. When LAK cells were treated with neuraminidase (0.5 units/ml), and transfused into hepatectomized mice, more potent suppression of liver regeneration was induced in comparison with the same dose of LAK cells. The intraperitoneal injection of recombinant interleukin 2 (rIL-2) after partial hepatectomy also inhibited the regeneration of remnant liver. From these results, lymphocytes such as LAK cells appear to regulate liver regeneration.