Thiopurines inhibit coronavirus Spike protein processing and incorporation into progeny virions.
There is an outstanding need for broadly acting antiviral drugs to combat emerging viral diseases. Here, we report that thiopurines inhibit the replication of the betacoronaviruses HCoV-OC43 and SARS-CoV-2. 6-Thioguanine (6-TG) disrupted early stages of infection, limiting accumulation of full-lengt...
| Main Authors: | , , , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2022-09-01
|
| Series: | PLoS Pathogens |
| Online Access: | https://doi.org/10.1371/journal.ppat.1010832 |
| _version_ | 1828106830081949696 |
|---|---|
| author | Eric S Pringle Brett A Duguay Maxwell P Bui-Marinos Rory P Mulloy Shelby L Landreth Krishna Swaroop Desireddy Stacia M Dolliver Shan Ying Taylor Caddell Trinity H Tooley Patrick D Slaine Stephen L Bearne Darryl Falzarano Jennifer A Corcoran Denys A Khaperskyy Craig McCormick |
| author_facet | Eric S Pringle Brett A Duguay Maxwell P Bui-Marinos Rory P Mulloy Shelby L Landreth Krishna Swaroop Desireddy Stacia M Dolliver Shan Ying Taylor Caddell Trinity H Tooley Patrick D Slaine Stephen L Bearne Darryl Falzarano Jennifer A Corcoran Denys A Khaperskyy Craig McCormick |
| author_sort | Eric S Pringle |
| collection | DOAJ |
| description | There is an outstanding need for broadly acting antiviral drugs to combat emerging viral diseases. Here, we report that thiopurines inhibit the replication of the betacoronaviruses HCoV-OC43 and SARS-CoV-2. 6-Thioguanine (6-TG) disrupted early stages of infection, limiting accumulation of full-length viral genomes, subgenomic RNAs and structural proteins. In ectopic expression models, we observed that 6-TG increased the electrophoretic mobility of Spike from diverse betacoronaviruses, matching the effects of enzymatic removal of N-linked oligosaccharides from Spike in vitro. SARS-CoV-2 virus-like particles (VLPs) harvested from 6-TG-treated cells were deficient in Spike. 6-TG treatment had a similar effect on production of lentiviruses pseudotyped with SARS-CoV-2 Spike, yielding pseudoviruses deficient in Spike and unable to infect ACE2-expressing cells. Together, these findings from complementary ectopic expression and infection models strongly indicate that defective Spike trafficking and processing is an outcome of 6-TG treatment. Using biochemical and genetic approaches we demonstrated that 6-TG is a pro-drug that must be converted to the nucleotide form by hypoxanthine phosphoribosyltransferase 1 (HPRT1) to achieve antiviral activity. This nucleotide form has been shown to inhibit small GTPases Rac1, RhoA, and CDC42; however, we observed that selective chemical inhibitors of these GTPases had no effect on Spike processing or accumulation. By contrast, the broad GTPase agonist ML099 countered the effects of 6-TG, suggesting that the antiviral activity of 6-TG requires the targeting of an unknown GTPase. Overall, these findings suggest that small GTPases are promising targets for host-targeted antivirals. |
| first_indexed | 2024-04-11T10:23:11Z |
| format | Article |
| id | doaj.art-e4051cc5cb3d4a36881ae54bc20ae244 |
| institution | Directory Open Access Journal |
| issn | 1553-7366 1553-7374 |
| language | English |
| last_indexed | 2024-04-11T10:23:11Z |
| publishDate | 2022-09-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Pathogens |
| spelling | doaj.art-e4051cc5cb3d4a36881ae54bc20ae2442022-12-22T04:29:41ZengPublic Library of Science (PLoS)PLoS Pathogens1553-73661553-73742022-09-01189e101083210.1371/journal.ppat.1010832Thiopurines inhibit coronavirus Spike protein processing and incorporation into progeny virions.Eric S PringleBrett A DuguayMaxwell P Bui-MarinosRory P MulloyShelby L LandrethKrishna Swaroop DesireddyStacia M DolliverShan YingTaylor CaddellTrinity H TooleyPatrick D SlaineStephen L BearneDarryl FalzaranoJennifer A CorcoranDenys A KhaperskyyCraig McCormickThere is an outstanding need for broadly acting antiviral drugs to combat emerging viral diseases. Here, we report that thiopurines inhibit the replication of the betacoronaviruses HCoV-OC43 and SARS-CoV-2. 6-Thioguanine (6-TG) disrupted early stages of infection, limiting accumulation of full-length viral genomes, subgenomic RNAs and structural proteins. In ectopic expression models, we observed that 6-TG increased the electrophoretic mobility of Spike from diverse betacoronaviruses, matching the effects of enzymatic removal of N-linked oligosaccharides from Spike in vitro. SARS-CoV-2 virus-like particles (VLPs) harvested from 6-TG-treated cells were deficient in Spike. 6-TG treatment had a similar effect on production of lentiviruses pseudotyped with SARS-CoV-2 Spike, yielding pseudoviruses deficient in Spike and unable to infect ACE2-expressing cells. Together, these findings from complementary ectopic expression and infection models strongly indicate that defective Spike trafficking and processing is an outcome of 6-TG treatment. Using biochemical and genetic approaches we demonstrated that 6-TG is a pro-drug that must be converted to the nucleotide form by hypoxanthine phosphoribosyltransferase 1 (HPRT1) to achieve antiviral activity. This nucleotide form has been shown to inhibit small GTPases Rac1, RhoA, and CDC42; however, we observed that selective chemical inhibitors of these GTPases had no effect on Spike processing or accumulation. By contrast, the broad GTPase agonist ML099 countered the effects of 6-TG, suggesting that the antiviral activity of 6-TG requires the targeting of an unknown GTPase. Overall, these findings suggest that small GTPases are promising targets for host-targeted antivirals.https://doi.org/10.1371/journal.ppat.1010832 |
| spellingShingle | Eric S Pringle Brett A Duguay Maxwell P Bui-Marinos Rory P Mulloy Shelby L Landreth Krishna Swaroop Desireddy Stacia M Dolliver Shan Ying Taylor Caddell Trinity H Tooley Patrick D Slaine Stephen L Bearne Darryl Falzarano Jennifer A Corcoran Denys A Khaperskyy Craig McCormick Thiopurines inhibit coronavirus Spike protein processing and incorporation into progeny virions. PLoS Pathogens |
| title | Thiopurines inhibit coronavirus Spike protein processing and incorporation into progeny virions. |
| title_full | Thiopurines inhibit coronavirus Spike protein processing and incorporation into progeny virions. |
| title_fullStr | Thiopurines inhibit coronavirus Spike protein processing and incorporation into progeny virions. |
| title_full_unstemmed | Thiopurines inhibit coronavirus Spike protein processing and incorporation into progeny virions. |
| title_short | Thiopurines inhibit coronavirus Spike protein processing and incorporation into progeny virions. |
| title_sort | thiopurines inhibit coronavirus spike protein processing and incorporation into progeny virions |
| url | https://doi.org/10.1371/journal.ppat.1010832 |
| work_keys_str_mv | AT ericspringle thiopurinesinhibitcoronavirusspikeproteinprocessingandincorporationintoprogenyvirions AT brettaduguay thiopurinesinhibitcoronavirusspikeproteinprocessingandincorporationintoprogenyvirions AT maxwellpbuimarinos thiopurinesinhibitcoronavirusspikeproteinprocessingandincorporationintoprogenyvirions AT rorypmulloy thiopurinesinhibitcoronavirusspikeproteinprocessingandincorporationintoprogenyvirions AT shelbyllandreth thiopurinesinhibitcoronavirusspikeproteinprocessingandincorporationintoprogenyvirions AT krishnaswaroopdesireddy thiopurinesinhibitcoronavirusspikeproteinprocessingandincorporationintoprogenyvirions AT staciamdolliver thiopurinesinhibitcoronavirusspikeproteinprocessingandincorporationintoprogenyvirions AT shanying thiopurinesinhibitcoronavirusspikeproteinprocessingandincorporationintoprogenyvirions AT taylorcaddell thiopurinesinhibitcoronavirusspikeproteinprocessingandincorporationintoprogenyvirions AT trinityhtooley thiopurinesinhibitcoronavirusspikeproteinprocessingandincorporationintoprogenyvirions AT patrickdslaine thiopurinesinhibitcoronavirusspikeproteinprocessingandincorporationintoprogenyvirions AT stephenlbearne thiopurinesinhibitcoronavirusspikeproteinprocessingandincorporationintoprogenyvirions AT darrylfalzarano thiopurinesinhibitcoronavirusspikeproteinprocessingandincorporationintoprogenyvirions AT jenniferacorcoran thiopurinesinhibitcoronavirusspikeproteinprocessingandincorporationintoprogenyvirions AT denysakhaperskyy thiopurinesinhibitcoronavirusspikeproteinprocessingandincorporationintoprogenyvirions AT craigmccormick thiopurinesinhibitcoronavirusspikeproteinprocessingandincorporationintoprogenyvirions |