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Basic Characteristics of Mutations
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Mutation Site
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P50H |
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Mutation Site Sentence
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No influence for HBsAg production was found by these Cp mutants (p >0.05, Fig. 5A), whereas production and secretion of HBeAg were affected by a single aa reparation or mutation at Cp aa position 50 or 62, and were considerably reduced by the combination of mutations P50H/W62R or P50H/W62R/S74G (p <0.05 or 0.01, Fig. 5B). |
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Mutation Level
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Amino acid level |
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Mutation Type
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Nonsynonymous substitution |
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Gene/Protein/Region
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C |
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Standardized Encoding Gene
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C
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Genotype/Subtype
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B |
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Viral Reference
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-
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Functional Impact and Mechanisms
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Disease
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Occult HBV Infection
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Immune
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Y |
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Target Gene
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-
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Clinical and Epidemiological Correlations
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Clinical Information
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Y |
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Treatment
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- |
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Location
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- |
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Literature Information
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PMID
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33453326
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Title
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Role of core protein mutations in the development of occult HBV infection
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Author
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Chen J,Liu B,Tang X,Zheng X,Lu J,Zhang L,Wang W,Candotti D,Fu Y,Allain JP,Li C,Li L,Li T
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Journal
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Journal of hepatology
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Journal Info
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2021 Jun;74(6):1303-1314
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Abstract
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BACKGROUND & AIMS: Occult HBV infection (OBI) is associated with transfusion-transmitted HBV infection and hepatocellular carcinoma. Studies on OBI genesis have concentrated on mutations in the S region and the regulatory elements. Herein, we aimed to determine the role of mutations in the core region on OBIs. METHODS: An OBI strain (SZA) carrying 9 amino acid (aa) substitutions in the core protein/capsid (Cp) was selected by sequence alignment and Western blot analysis from 26 genotype B OBI samples to extensively explore the impact of Cp mutations on viral antigen production in vitro and in vivo. RESULTS: A large panel of 30 Cp replicons were generated by a replication-competent pHBV1.3 carrying SZA or wild-type (WT) Cp in a 1.3-fold over-length of HBV genome, in which the various Cp mutants were individually introduced by repairing site mutations of SZA-Cp or creating site mutations of WT-Cp by site-directed mutagenesis. The expression of HBcAg, HBeAg, and HBsAg and viral RNA was quantified from individual SZA and WT Cp mutant replicons in transfected Huh7 cells or infected mice, respectively. An analysis of the effect of Cp mutants on intracellular or extracellular viral protein production indicated that the W62R mutation in Cp had a critical impact on the reduction of HBcAg and HBeAg production during HBV replication, whereas P50H and/or S74G mutations played a limited role in influencing viral protein production invivo. CONCLUSIONS: W62R and its combination mutations in HBV Cp might massively affect HBcAg and HBeAg production during viral replication, which, in turn, might contribute to the occurrence of OBI. LAY SUMMARY: Occult hepatitis B virus infections (OBIs) have been found to be associated with amino acid mutations in the S region of the HBV, but the role of mutations in the core protein (Cp) remains unclear. In this study, an OBI strain (SZA) carrying 9 amino acid substitutions in Cp has been examined comprehensively in vitro and in vivo. The W62R mutation in Cp majorly reduces HBcAg and HBeAg production during HBV replication, potentially contributing to the occurrence of OBI.
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Sequence Data
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-
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