SARS-CoV-2 nsp15 endoribonuclease antagonizes dsRNA-induced antiviral signaling

作者：Clayton J. Otter, Nicole R. Bracci, Nicholas A. Parenti, Chengjin Ye, Abhishek Asthana, Ebba K. Blomqvist, Li Tan, Jessica J. Pfannenstiel, Nathaniel D. Jackson, Anthony R. Fehr, Robert H. Silverman, James M. Burke, Noam A. Cohen, Luis Martínez‐Sobrido, Susan Reich Weiss · 发表于：Proceedings of the National Academy of Sciences · 年份：2024 · DOI：10.1073/pnas.2320194121 · 被引用次数：54 · 研究领域：SARS-CoV-2 and COVID-19 Research、RNA regulation and disease、interferon and immune responses

Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 has caused millions of deaths since its emergence in 2019. Innate immune antagonism by lethal CoVs such as SARS-CoV-2 is crucial for optimal replication and pathogenesis. The conserved nonstructural protein 15 (nsp15) endoribonuclease (EndoU) limits activation of double-stranded (ds)RNA-induced pathways, including interferon (IFN) signaling, protein kinase R (PKR), and oligoadenylate synthetase/ribonuclease L (OAS/RNase L) during diverse CoV infections including murine coronavirus and Middle East respiratory syndrome (MERS)-CoV. To determine how nsp15 functions during SARS-CoV-2 infection, we constructed a recombinant SARS-CoV-2 (nsp15 mut ) expressing catalytically inactivated nsp15, which we show promoted increased dsRNA accumulation. Infection with SARS-CoV-2 nsp15 mut led to increased activation of the IFN signaling and PKR pathways in lung-derived epithelial cell lines and primary nasal epithelial air–liquid interface (ALI) cultures as well as significant attenuation of replication in ALI cultures compared to wild-type virus. This replication defect was rescued when IFN signaling was inhibited with the Janus activated kinase (JAK) inhibitor ruxolitinib. Finally, to assess nsp15 function in the context of minimal (MERS-CoV) or moderate (SARS-CoV-2) innate immune induction, we compared infections with SARS-CoV-2 nsp15 mut and previously described MERS-CoV nsp15 mutants. Inactivation of nsp15 had a more dramatic imp...