Fig. 1.
IFN-α kills HCs by apoptosis.
HCs were cultured with or without IFN-α (0-1000 U/mL as indicated) at a density of 106/mL in RPMI plus 0.5% BSA in tissue culture plates coated with polyHEMA. Cell death was measured by FACS analysis of cells stained with DiOC6 and PI (A,C). DiOC6 is selectively concentrated in polarized mitochondria of live cells, whereas PI is excluded from such cells. Apoptosis was detected as DNA fragmentation (B) or PARP-1 cleavage (D). A representative example is shown from among the 4 cases tested. Although IFN-α produced dose-dependent killing in all 4 cases, the results were not pooled because the time taken for appreciable killing differed markedly between cases (6-14 days).
