ABSTRACT
Interferons (IFNs) are induced proteins that render cells resistant to virus replication. Since the discovery of IFN by Isaacs and Lindenmann in 1957, studies have established that IFNs mediate many different actions in vitro, some of which could conceivably alter host resistance only to virus, but also to other infectious agents, as well as to malignant disease. While an enormous amount of time and effort has been given to the study of IFNs since 1957, little is known about whether IFNs actually function in host defense against nonviral or malignant diseases. The most plausible function of these Listeria-induced antiviral molecules would be to protect the compromised host from concurrent virus infection. However, in addition to antiviral actions, IFNs are known to mediate actions which could alter host resistance to nonviral infections. The response of mice to L. monocytogenes provides excellent model for studying the possible roles of IFNs in nonspecific resistance and acquired specific resistance to a facultative intracellular pathogen.
