Discovery of bimodal hepatitis B virus ribonuclease H and capsid assembly inhibitors.
Hepatitis B virus (HBV) ribonuclease H (RNaseH) inhibitors are a potent class of antivirals that prevent degradation of the viral pregenomic RNA during reverse transcription and block formation of mature HBV DNAs. Development of HBV RNaseH inhibitors is entering advanced preclinical analyses. To ens...
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Public Library of Science (PLoS)
2025-02-01
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| Series: | PLoS Pathogens |
| Online Access: | https://doi.org/10.1371/journal.ppat.1012920 |
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| author | Daniel P Bradley Caleb J Valkner Qilan Li Makafui Gasonoo Marvin J Meyers Georgia-Myrto Prifti Dimitrios Moianos Grigoris Zoidis Adam Zlotnick John E Tavis |
| author_facet | Daniel P Bradley Caleb J Valkner Qilan Li Makafui Gasonoo Marvin J Meyers Georgia-Myrto Prifti Dimitrios Moianos Grigoris Zoidis Adam Zlotnick John E Tavis |
| author_sort | Daniel P Bradley |
| collection | DOAJ |
| description | Hepatitis B virus (HBV) ribonuclease H (RNaseH) inhibitors are a potent class of antivirals that prevent degradation of the viral pregenomic RNA during reverse transcription and block formation of mature HBV DNAs. Development of HBV RNaseH inhibitors is entering advanced preclinical analyses. To ensure the mechanism of action was fully understood, we defined the effects of RNaseH inhibitors on other steps of HBV replication. Some N-hydroxypyridinedione (HPD) HBV RNaseH inhibitors significantly reduced accumulation of capsids in HBV-replicating cells. A representative HPD 1466, with a 50% effective concentration against HBV replication of 0.25 µM, decreased capsid and core protein accumulation by 50-90% in HepDES19 and HepG2.2.15 cells. Surprisingly, 1466 did not affect pregenomic RNA encapsidation, demonstrating a specific effect on empty capsids. HBV genomic replication was not necessary for 1466's inhibitory effect as it decreased capsid accumulation in cells transfected with replication-deficient mutants blocking pgRNA encapsidation (Δ-bulge), DNA synthesis (YMHA), and RNaseH (D702A) activities. 1466 also decreased capsid and core protein accumulation in cells transfected with a core protein expression plasmid, indicating that other HBV products are unneeded. 1466 reduced initial capsid assembly rates in biochemical assembly reactions employing purified core protein (Cp149), demonstrating a specific effect on HBV core protein. We conclude that the bimodal HPD HBV RNaseH inhibitor 1466 is the prototypic member of a new class of capsid assembly modulators (CAM) that inhibits capsid assembly rather than accelerating it, as all other CAM classes do. We propose that this class be called CAM-I, for CAM-inhibitor. These results lay the foundation for identifying bimodal HBV antivirals targeting the RNaseH and capsid assembly. |
| format | Article |
| id | doaj-art-feac6a4a27174b17ade952d7e33ff13c |
| institution | DOAJ |
| issn | 1553-7366 1553-7374 |
| language | English |
| publishDate | 2025-02-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Pathogens |
| spelling | doaj-art-feac6a4a27174b17ade952d7e33ff13c2025-08-20T03:12:32ZengPublic Library of Science (PLoS)PLoS Pathogens1553-73661553-73742025-02-01212e101292010.1371/journal.ppat.1012920Discovery of bimodal hepatitis B virus ribonuclease H and capsid assembly inhibitors.Daniel P BradleyCaleb J ValknerQilan LiMakafui GasonooMarvin J MeyersGeorgia-Myrto PriftiDimitrios MoianosGrigoris ZoidisAdam ZlotnickJohn E TavisHepatitis B virus (HBV) ribonuclease H (RNaseH) inhibitors are a potent class of antivirals that prevent degradation of the viral pregenomic RNA during reverse transcription and block formation of mature HBV DNAs. Development of HBV RNaseH inhibitors is entering advanced preclinical analyses. To ensure the mechanism of action was fully understood, we defined the effects of RNaseH inhibitors on other steps of HBV replication. Some N-hydroxypyridinedione (HPD) HBV RNaseH inhibitors significantly reduced accumulation of capsids in HBV-replicating cells. A representative HPD 1466, with a 50% effective concentration against HBV replication of 0.25 µM, decreased capsid and core protein accumulation by 50-90% in HepDES19 and HepG2.2.15 cells. Surprisingly, 1466 did not affect pregenomic RNA encapsidation, demonstrating a specific effect on empty capsids. HBV genomic replication was not necessary for 1466's inhibitory effect as it decreased capsid accumulation in cells transfected with replication-deficient mutants blocking pgRNA encapsidation (Δ-bulge), DNA synthesis (YMHA), and RNaseH (D702A) activities. 1466 also decreased capsid and core protein accumulation in cells transfected with a core protein expression plasmid, indicating that other HBV products are unneeded. 1466 reduced initial capsid assembly rates in biochemical assembly reactions employing purified core protein (Cp149), demonstrating a specific effect on HBV core protein. We conclude that the bimodal HPD HBV RNaseH inhibitor 1466 is the prototypic member of a new class of capsid assembly modulators (CAM) that inhibits capsid assembly rather than accelerating it, as all other CAM classes do. We propose that this class be called CAM-I, for CAM-inhibitor. These results lay the foundation for identifying bimodal HBV antivirals targeting the RNaseH and capsid assembly.https://doi.org/10.1371/journal.ppat.1012920 |
| spellingShingle | Daniel P Bradley Caleb J Valkner Qilan Li Makafui Gasonoo Marvin J Meyers Georgia-Myrto Prifti Dimitrios Moianos Grigoris Zoidis Adam Zlotnick John E Tavis Discovery of bimodal hepatitis B virus ribonuclease H and capsid assembly inhibitors. PLoS Pathogens |
| title | Discovery of bimodal hepatitis B virus ribonuclease H and capsid assembly inhibitors. |
| title_full | Discovery of bimodal hepatitis B virus ribonuclease H and capsid assembly inhibitors. |
| title_fullStr | Discovery of bimodal hepatitis B virus ribonuclease H and capsid assembly inhibitors. |
| title_full_unstemmed | Discovery of bimodal hepatitis B virus ribonuclease H and capsid assembly inhibitors. |
| title_short | Discovery of bimodal hepatitis B virus ribonuclease H and capsid assembly inhibitors. |
| title_sort | discovery of bimodal hepatitis b virus ribonuclease h and capsid assembly inhibitors |
| url | https://doi.org/10.1371/journal.ppat.1012920 |
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