HBV capsid assembly modulators differentially modulate the assembly of wild-type and drug-resistant core protein chimeric nucleocapsids and empty capsids.

Multiple capsid assembly modulators (CAMs) are in clinical development for the treatment of chronic hepatitis B. The emergence of CAM-resistant HBV has resulted in the failure of CAM antiviral therapy in recent clinical trials. Because wild-type (WT) and CAM-resistant core protein (Cp) can co-assemb...

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Main Authors: Hui Liu, Hemraj Rimal, Jun Lyu, Liangxian Shen, Qiong Zhao, Jinhong Chang, Ju-Tao Guo
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2025-08-01
Series:PLoS Pathogens
Online Access:https://doi.org/10.1371/journal.ppat.1013391
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author Hui Liu
Hemraj Rimal
Jun Lyu
Liangxian Shen
Qiong Zhao
Jinhong Chang
Ju-Tao Guo
author_facet Hui Liu
Hemraj Rimal
Jun Lyu
Liangxian Shen
Qiong Zhao
Jinhong Chang
Ju-Tao Guo
author_sort Hui Liu
collection DOAJ
description Multiple capsid assembly modulators (CAMs) are in clinical development for the treatment of chronic hepatitis B. The emergence of CAM-resistant HBV has resulted in the failure of CAM antiviral therapy in recent clinical trials. Because wild-type (WT) and CAM-resistant core protein (Cp) can co-assemble to form chimeric capsids, it is important to understand how CAMs modulate the assembly and disassembly of chimeric capsids and how CAM-resistant HBV variants emerge under CAM antiviral therapy. In addressing these questions, we found that in human hepatoma cells co-transfected with a serial molar ratio of WT and mutant HBV replicons expressing CAM-resistant Cp, expression of as few as 10% WT Cp conferred inhibition of nucleocapsid assembly by CAMs. However, 50% Cp with T33N substitution conferred complete resistance to the assembly of chimeric empty capsids induced by AB-506 but remained sensitive to GLS4, as determined in an in vitro capsid assembly assay and in transfected hepatoma cells. Moreover, the existence of approximately 50% WT Cp in chimeric nucleocapsids is required for CAMs to induce the disassembly of mature nucleocapsids and inhibit the infection of hepatocytes by HBV virions with chimeric nucleocapsids. Our results thus suggest that although disruption of nucleocapsid assembly requires only small numbers of CAM binding pockets at Cp dimer-dimer interfaces to be engaged, induction of mature nucleocapsid disassembly requires much larger numbers of CAM binding pockets to be occupied. The strong WT Cp dominance in CAM suppression of nucleocapsid assembly may slow down the emergence of CAM-resistant HBV variants under CAM therapy.
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institution Kabale University
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spelling doaj-art-d10e0a37c48c40669d1ff9e81d1a8f5d2025-08-23T05:31:24ZengPublic Library of Science (PLoS)PLoS Pathogens1553-73661553-73742025-08-01218e101339110.1371/journal.ppat.1013391HBV capsid assembly modulators differentially modulate the assembly of wild-type and drug-resistant core protein chimeric nucleocapsids and empty capsids.Hui LiuHemraj RimalJun LyuLiangxian ShenQiong ZhaoJinhong ChangJu-Tao GuoMultiple capsid assembly modulators (CAMs) are in clinical development for the treatment of chronic hepatitis B. The emergence of CAM-resistant HBV has resulted in the failure of CAM antiviral therapy in recent clinical trials. Because wild-type (WT) and CAM-resistant core protein (Cp) can co-assemble to form chimeric capsids, it is important to understand how CAMs modulate the assembly and disassembly of chimeric capsids and how CAM-resistant HBV variants emerge under CAM antiviral therapy. In addressing these questions, we found that in human hepatoma cells co-transfected with a serial molar ratio of WT and mutant HBV replicons expressing CAM-resistant Cp, expression of as few as 10% WT Cp conferred inhibition of nucleocapsid assembly by CAMs. However, 50% Cp with T33N substitution conferred complete resistance to the assembly of chimeric empty capsids induced by AB-506 but remained sensitive to GLS4, as determined in an in vitro capsid assembly assay and in transfected hepatoma cells. Moreover, the existence of approximately 50% WT Cp in chimeric nucleocapsids is required for CAMs to induce the disassembly of mature nucleocapsids and inhibit the infection of hepatocytes by HBV virions with chimeric nucleocapsids. Our results thus suggest that although disruption of nucleocapsid assembly requires only small numbers of CAM binding pockets at Cp dimer-dimer interfaces to be engaged, induction of mature nucleocapsid disassembly requires much larger numbers of CAM binding pockets to be occupied. The strong WT Cp dominance in CAM suppression of nucleocapsid assembly may slow down the emergence of CAM-resistant HBV variants under CAM therapy.https://doi.org/10.1371/journal.ppat.1013391
spellingShingle Hui Liu
Hemraj Rimal
Jun Lyu
Liangxian Shen
Qiong Zhao
Jinhong Chang
Ju-Tao Guo
HBV capsid assembly modulators differentially modulate the assembly of wild-type and drug-resistant core protein chimeric nucleocapsids and empty capsids.
PLoS Pathogens
title HBV capsid assembly modulators differentially modulate the assembly of wild-type and drug-resistant core protein chimeric nucleocapsids and empty capsids.
title_full HBV capsid assembly modulators differentially modulate the assembly of wild-type and drug-resistant core protein chimeric nucleocapsids and empty capsids.
title_fullStr HBV capsid assembly modulators differentially modulate the assembly of wild-type and drug-resistant core protein chimeric nucleocapsids and empty capsids.
title_full_unstemmed HBV capsid assembly modulators differentially modulate the assembly of wild-type and drug-resistant core protein chimeric nucleocapsids and empty capsids.
title_short HBV capsid assembly modulators differentially modulate the assembly of wild-type and drug-resistant core protein chimeric nucleocapsids and empty capsids.
title_sort hbv capsid assembly modulators differentially modulate the assembly of wild type and drug resistant core protein chimeric nucleocapsids and empty capsids
url https://doi.org/10.1371/journal.ppat.1013391
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