tetano
Editor, Senior Moderator
Proc Natl Acad Sci U S A
. 2023 Aug 29;120(35):e2302083120.
doi: 10.1073/pnas.2302083120. Epub 2023 Aug 22. SARS-CoV-2 Mac1 is required for IFN antagonism and efficient virus replication in cell culture and in mice
Yousef M Alhammad[SUP] #[/SUP][SUP] 1 [/SUP], Srivatsan Parthasarathy[SUP] #[/SUP][SUP] 1 [/SUP], Roshan Ghimire[SUP] #[/SUP][SUP] 2 [/SUP], Catherine M Kerr[SUP] 1 [/SUP], Joseph J O'Connor[SUP] 1 [/SUP], Jessica J Pfannenstiel[SUP] 1 [/SUP], Debarati Chanda[SUP] 2 [/SUP], Caden A Miller[SUP] 2 [/SUP], Nathalie Baumlin[SUP] 3 [/SUP], Matthias Salathe[SUP] 3 [/SUP], Robert L Unckless[SUP] 1 [/SUP], Sonia Zuñiga[SUP] 4 [/SUP], Luis Enjuanes[SUP] 4 [/SUP], Sunil More[SUP] 2 [/SUP], Rudragouda Channappanavar[SUP] 2 [/SUP], Anthony R Fehr[SUP] 1 [/SUP]
Affiliations
Several coronavirus (CoV) encoded proteins are being evaluated as targets for antiviral therapies for COVID-19. Included in these drug targets is the conserved macrodomain, or Mac1, an ADP-ribosylhydrolase and ADP-ribose binding protein encoded as a small domain at the N terminus of nonstructural protein 3. Utilizing point mutant recombinant viruses, Mac1 was shown to be critical for both murine hepatitis virus (MHV) and severe acute respiratory syndrome (SARS)-CoV virulence. However, as a potential drug target, it is imperative to understand how a complete Mac1 deletion impacts the replication and pathogenesis of different CoVs. To this end, we created recombinant bacterial artificial chromosomes (BACs) containing complete Mac1 deletions (ΔMac1) in MHV, MERS-CoV, and SARS-CoV-2. While we were unable to recover infectious virus from MHV or MERS-CoV ΔMac1 BACs, SARS-CoV-2 ΔMac1 was readily recovered from BAC transfection, indicating a stark difference in the requirement for Mac1 between different CoVs. Furthermore, SARS-CoV-2 ΔMac1 replicated at or near wild-type levels in multiple cell lines susceptible to infection. However, in a mouse model of severe infection, ΔMac1 was quickly cleared causing minimal pathology without any morbidity. ΔMac1 SARS-CoV-2 induced increased levels of interferon (IFN) and IFN-stimulated gene expression in cell culture and mice, indicating that Mac1 blocks IFN responses which may contribute to its attenuation. ΔMac1 infection also led to a stark reduction in inflammatory monocytes and neutrophils. These results demonstrate that Mac1 only minimally impacts SARS-CoV-2 replication, unlike MHV and MERS-CoV, but is required for SARS-CoV-2 pathogenesis and is a unique antiviral drug target.
Keywords: ADP-ribosylation; SARS-CoV-2; coronavirus; interferon; macrodomain.
. 2023 Aug 29;120(35):e2302083120.
doi: 10.1073/pnas.2302083120. Epub 2023 Aug 22. SARS-CoV-2 Mac1 is required for IFN antagonism and efficient virus replication in cell culture and in mice
Yousef M Alhammad[SUP] #[/SUP][SUP] 1 [/SUP], Srivatsan Parthasarathy[SUP] #[/SUP][SUP] 1 [/SUP], Roshan Ghimire[SUP] #[/SUP][SUP] 2 [/SUP], Catherine M Kerr[SUP] 1 [/SUP], Joseph J O'Connor[SUP] 1 [/SUP], Jessica J Pfannenstiel[SUP] 1 [/SUP], Debarati Chanda[SUP] 2 [/SUP], Caden A Miller[SUP] 2 [/SUP], Nathalie Baumlin[SUP] 3 [/SUP], Matthias Salathe[SUP] 3 [/SUP], Robert L Unckless[SUP] 1 [/SUP], Sonia Zuñiga[SUP] 4 [/SUP], Luis Enjuanes[SUP] 4 [/SUP], Sunil More[SUP] 2 [/SUP], Rudragouda Channappanavar[SUP] 2 [/SUP], Anthony R Fehr[SUP] 1 [/SUP]
Affiliations
- PMID: 37607224
- DOI: 10.1073/pnas.2302083120
Several coronavirus (CoV) encoded proteins are being evaluated as targets for antiviral therapies for COVID-19. Included in these drug targets is the conserved macrodomain, or Mac1, an ADP-ribosylhydrolase and ADP-ribose binding protein encoded as a small domain at the N terminus of nonstructural protein 3. Utilizing point mutant recombinant viruses, Mac1 was shown to be critical for both murine hepatitis virus (MHV) and severe acute respiratory syndrome (SARS)-CoV virulence. However, as a potential drug target, it is imperative to understand how a complete Mac1 deletion impacts the replication and pathogenesis of different CoVs. To this end, we created recombinant bacterial artificial chromosomes (BACs) containing complete Mac1 deletions (ΔMac1) in MHV, MERS-CoV, and SARS-CoV-2. While we were unable to recover infectious virus from MHV or MERS-CoV ΔMac1 BACs, SARS-CoV-2 ΔMac1 was readily recovered from BAC transfection, indicating a stark difference in the requirement for Mac1 between different CoVs. Furthermore, SARS-CoV-2 ΔMac1 replicated at or near wild-type levels in multiple cell lines susceptible to infection. However, in a mouse model of severe infection, ΔMac1 was quickly cleared causing minimal pathology without any morbidity. ΔMac1 SARS-CoV-2 induced increased levels of interferon (IFN) and IFN-stimulated gene expression in cell culture and mice, indicating that Mac1 blocks IFN responses which may contribute to its attenuation. ΔMac1 infection also led to a stark reduction in inflammatory monocytes and neutrophils. These results demonstrate that Mac1 only minimally impacts SARS-CoV-2 replication, unlike MHV and MERS-CoV, but is required for SARS-CoV-2 pathogenesis and is a unique antiviral drug target.
Keywords: ADP-ribosylation; SARS-CoV-2; coronavirus; interferon; macrodomain.