Double-stranded RNA induces S100 gene expression by a cycloheximide-sensitive factor.

Viral double-stranded RNA (dsRNA) and its synthetic analog polyI:C are recognized via multiple pathways and induce the expression of genes related to inflammation. In the present study, we demonstrated the polyI:C-induced gene expression of the damage associated molecular pattern (DAMP) molecules S100A8 and S100A9, while other S100 genes were not affected. Cycloheximide and Brefeldin A treatment revealed both the expression of S100A8 and S100A9 as secondary response genes and the involvement of polyI:C-induced cytokines herein. Several type I and type III interferons such as IFNβ, IL-20, IL-24, and IFNλ/IL-29 were expressed in response to polyI:C, however, they failed to induce S100A8 and S100A9 gene expression. These data indicate the involvement of the danger molecule S100A8/A9 in the resistance against viruses.