Topoisomerase III-ß is required for efficient replication of positive-sense RNA viruses

K. Reddisiva Prasanth; Minato Hirano; W. Samuel Fagg; Eileen T. McAnarney; Chao Shan; Xuping Xie; Adam Hage; Colette A. Pietzsch; Alexander Bukreyev; Ricardo Rajsbaum; Pei-Yong Shi; Mark T. Bedford; Shelton S. Bradrick; Vineet Menachery; Mariano A. Garcia-Blanco

Since TOP3B was required for DENV-2, YFV and ZIKV replication, we asked whether or not this topoisomerase was required for replication of other viruses. Influenza A virus, which has a negative-sense segmented RNA genome and belongs to the family Orthomyxoviridae, replicated significantly better in TOP3B KO cells than in the parental HuH-7 cells (Fig 2A, left panel), suggesting that TOP3B plays an anti-viral role for influenza A virus. We also tested Ebola virus, a member of the family Filoviridae, which has a negative sense RNA genome and again noted that Ebola virus replicated slightly better in TOP3B KO cells than in the parental HuH-7 cells (Fig 2A, right panel) . We thus suggest that TOP3B may be an anti-viral factor for negative sense RNA viruses, and clearly is not required for the replication of influenza A virus or Ebola virus.