Released Tryptophanyl-tRNA Synthetase Stimulates Innate Immune Responses against Viral Infection

ARSs are essential enzymes in translation that link specific amino acids to their cognate tRNAs. In higher eukaryotes, some ARSs possess additional, noncanonical functions in the regulation of cell metabolism. Here, we report a novel noncanonical function of WRS in antiviral defense. WRS is rapidly secreted in response to viral infection and primes the innate immune response by inducing the secretion of proinflammatory cytokines and type I IFNs, resulting in the inhibition of virus replication both in vitro and in vivo . Thus, we consider WRS to be a member of the antiviral innate immune response. The results of this study enhance our understanding of host defense systems and provide additional information on the noncanonical functions of ARSs.