Antiviral Actions of Double-Stranded RNA

The host responds to virus infection by triggering various antiviral defense mechanisms, many of which are initiated by double-stranded (ds) RNA, which is often produced in virus-infected cells. Surprisingly, similar responses are also triggered by cellular dsRNA produced by necrotic, or otherwise stressed, uninfected cells; in human and mouse, such responses have been genetically linked to protection against several diseases of non-viral etiology. Thus, dsRNA has a wide role in mediating host defense. DsRNA is recognized, in the cell, by a large family of dsRNA-binding proteins, some of which share similar structural motifs that mediate the binding. Functionally, some of these proteins are dsRNA-dependent enzymes while others are signaling receptors that trigger transcription of a cohort of cellular genes, many of which encode antiviral proteins.