FUNCTIONAL-ROLE OF TYPE-I AND TYPE-II INTERFERONS IN ANTIVIRAL DEFENSE

Mice lacking the known subunit of the type I interferon (IFN) receptor were completely unresponsive to type I IFNs, suggesting that this rec eptor chain is essential for type I IFN-mediated signal transduction. These mice showed no overt anomalies but were unable to cope with vira l infections, despite otherwise normal immune responses. Comparison of mice lacking either type I or type II IFN receptors showed that, at l east in response to some viruses, both IFN systems are essential for a ntiviral defense and are functionally nonredundant.