Objective: To evaluate the replication and encapsidation of HBV mutants with the truncated C gene.
Methods: The HBV mutants with the truncated C gene were constructed by molecular cloning and PCR-based deletion in vitro. The replication and encapsidation of HBV mutants were investigated by Southern blotting, PCR and real-time fluorescence PCR respectively after transfecting the HBV mutants plasmid into HepG2 cells by using liposome.
Results: The C-truncated HBV mutant vectors were constructed successfully and confirmed exactly by clone sequencing and enzymes digestion. The C-truncated HBV mutants were replication defective, however, all types of HBV DNA could be detected positive in the cytoplasm and supernatant after co-transfecting the C-truncated HBV mutants plasmid and the helper constructs into HepG2 cells. The C-truncated HBV mutants were proved to produce 3-40 folds more progeny DNA than that of the wild-type HBV by DNA quantitative assay.
Conclusion: The C-truncated HBV mutants are replication-deficient and could not replicate and encapsulate in the hepatocytes when transfected solely, however, the progeny HBV-variant viruses are encapsidated more effectively to secrete into supernatant when co-transfected with the helper construct which lacks part of 5 prime-proximal HBV RNA packaging signal Epsilon.
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Front Microbiol
January 2025
Department of Microbiology, Faculty of Medicine, Shimane University, Izumo, Japan.
Current treatments for hepatitis B virus (HBV), such as interferons and nucleic acid analogs, have limitations due to side effects like depression and the development of drug-resistant mutants, highlighting the need for new therapeutic approaches. In this study, we identified microRNA-3145 (miR-3145) as a host-derived miRNA with antiviral activity that is upregulated in primary hepatocytes during HBV infection. The expression of its precursor, pri-miR-3145, increased in response to the the virus infection, and miR-3145 downregulated the hepatitis B virus S (HBS) antigen and hepatitis B virus X (HBX), thereby inhibiting viral replication.
View Article and Find Full Text PDFJ Clin Virol
January 2025
Division of Medical Microbiology and Virology, St. Paul's Hospital, Providence Health Care, Vancouver, British Columbia, Canada; Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada. Electronic address:
Background: Next-generation sequencing (NGS) for Hepatitis B virus (HBV) antiviral resistance (AVR) testing is a highly sensitive diagnostic method, able to detect low-level mutant subpopulations. Our clinical virology laboratory previously transitioned from DNA hybridization (INNO-LiPA) to NGS, initially with the GS Junior System and subsequently the MiSeq. The Oxford Nanopore Technology (ONT) sequencing system was evaluated for HBV resistance testing, with regards to sequencing accuracy and turn-around time.
View Article and Find Full Text PDFViruses
December 2024
Laboratory of Virology, National Institute for Infectious Diseases "Lazzaro Spallanzani" (IRCCS), 00149 Rome, Italy.
Persistence is a strategy used by many viruses to evade eradication by the immune system, ensuring their permanence and transmission within the host and optimizing viral fitness. During persistence, viruses can trigger various phenomena, including target organ damage, mainly due to an inflammatory state induced by infection, as well as cell proliferation and/or immortalization. In addition to immune evasion and chronic inflammation, factors contributing to viral persistence include low-level viral replication, the accumulation of viral mutants, and, most importantly, maintenance of the viral genome and reliance on viral oncoprotein production.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Microbiology, Faculty of Science, Kasetsart University, Bangkok, Thailand.
The "a" determinant, a highly conformational region within the hepatitis B virus large surface protein (LHBs), is crucial for antibody neutralization and diagnostic assays. Mutations in this area can lead to conformational changes, resulting in vaccination failure, diagnostic evasion, and disease progression. The "a" determinant of LHBs contains a conserved N-linked glycosylation site at N320, but the mechanisms of glycosylation in LHBs remain unclear.
View Article and Find Full Text PDFJ Med Virol
January 2025
Center of Infectious Diseases, West China Hospital of Sichuan University, Chengdu, China.
Glucose-regulated protein 78 kDa (GRP78), a key marker of endoplasmic reticulum stress (ERS), is upregulated in hepatocellular carcinoma (HCC) tissues, but its role in hepatitis B virus (HBV)-induced tumorigenesis remains unclear. This study aimed to investigate the contribution of GRP78 to HBV-associated tumor development and explore the ERS pathways involved. The results showed that increased GRP78 expression in patients with HBV-related HCC was associated with a poor prognosis within the first 2 years following diagnosis.
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