[Mechanism of the induction of apoptosis by influenza virus infection].

Influenza virus frequently causes acute respiratory inflammation. We and others have observed that influenza virus infection induces apoptosis both in vitro and in vivo. We found that the virus infection induces augmented Fas expression. We proposed that double-stranded RNA (dsRNA) activated protein kinase (PKR) is involved in Fas expression since a synthetic dsRNA activated Fas gene and exposure of the cells to anti-interferon-beta antibody, which decreased the PKR activity, suppressed the cell death, as well as an increase in Fas mRNA. Furthermore, transfecting the mutant PKR suppressed the augmented Fas expression and rendered the cells resistant to death upon virus infection. These results suggest that Fas gene activation in virus-infected cells is regulated by the PKR/interferon system.