IL15 and hepatitis A virus infection: To evaluate the role of these bystander activated CD8 T cells in inducing liver tissue damage, the authors showed that IL-15-activated CD8 T cells isolated from healthy controls and intrahepatic CD8 T cells isolated from the livers of acute hepatitis A (AHA) patients were capable of lysing K562 target cells which do not express MHC class I and also lysing liver-derived Huh-7 cells (55).