Hepatitis B core antigen (HBc or HBcAg) self-assembles into capsid particles and is extremely immunogenic. HBc has been extensively studied for its production in various expression systems and for the use of HBc particles for high-density, immunogenic presentation of foreign epitopes. Here we reported the high-level transient expression of HBc in plant leaf and its immunogenicity in mice. By using a novel plant viral expression system, HBc was produced in Nicotiana benthamiana leaves at levels up to 7.14% of total soluble protein (TSP) or 2.38 milligrams HBc per gram of fresh weight at 7 days post-infection (dpi). Plant-derived HBc (p-HBc) assembled into virus-like particles (VLPs) as revealed by sucrose gradients and electron microscopy. Partially purified p-HBc stimulated strong serum antibody responses in mice as Escherichia coli-derived HBc upon intraperitoneal (i.p.) injection. Furthermore, mice immunized mucosally (orally and intranasally) with p-HBc in the absence of adjuvants also developed HBc-specific serum IgG as well as intestinal IgA. Taken together, our results indicate the potential usefulness of p-HBc-VLP as a carrier for immunogenic presentation and mucosal delivery of foreign epitopes.
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http://dx.doi.org/10.1016/j.vaccine.2005.12.024 | DOI Listing |
PLoS Comput Biol
January 2025
Department of Gastroenterology and Hepatology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
Quantification of intrahepatic covalently closed circular DNA (cccDNA) is a key for evaluating an elimination of hepatitis B virus (HBV) in infected patients. However, quantifying cccDNA requires invasive methods such as a liver biopsy, which makes it impractical to access the dynamics of cccDNA in patients. Although HBV RNA and HBV core-related antigens (HBcrAg) have been proposed as surrogate markers for evaluating cccDNA activity, they do not necessarily estimate the amount of cccDNA.
View Article and Find Full Text PDFAIDS Behav
January 2025
Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Substance use and depression are prevalent in sexual and gender minorities (SGM), but evidence about their impacts on HIV pre-exposure prophylaxis (PrEP) use is mixed. We assessed these impacts in a US-based cohort of 3,330 young SGM who tested negative for HIV and completed baseline and semiannual assessments on substance use (cocaine, methamphetamine, or heroin), depression, and PrEP use and adherence. We estimated prevalence differences (PDs) to compare baseline and 12-month PrEP use and adherence between participants with and without substance use and depression, separately and jointly.
View Article and Find Full Text PDFViruses
December 2024
Department of Medicine & State Key Laboratory of Liver Research, School of Clinical Medicine, The University of Hong Kong, Hong Kong, China.
Full-length hepatitis B virus (HBV) transcripts of chimpanzees and patients treated with multidose (MD) HBV siRNA ARC-520 and entecavir (ETV) were characterized by single-molecule real-time (SMRT) sequencing, identifying multiple types of transcripts with the potential to encode HBx, HBsAg, HBeAg, core, and polymerase, as well as transcripts likely to be derived from dimers of dslDNA, and these differed between HBeAg-positive (HBeAg+) and HBeAg-negative (HBeAg-) individuals. HBV transcripts from the last follow-up ~30 months post-ARC-520 treatment were categorized from one HBeAg+ (one of two previously highly viremic patients that became HBeAg- upon treatment and had greatly reduced cccDNA products) and four HBeAg- patients. The previously HBeAg+ patient received a biopsy that revealed that he had 3.
View Article and Find Full Text PDFViruses
November 2024
Laboratory Branch, Division of HIV Prevention, National Center for HIV, Viral Hepatitis, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA.
The HIV integrase inhibitor, dolutegravir (DTG), in the absence of eliciting integrase (int) resistance, has been reported to select mutations in the virus 3'-polypurine tract (3'-PPT) adjacent to the 3'-LTR U3. An analog of DTG, cabotegravir (CAB), has a high genetic barrier to drug resistance and is used in formulations for treatment and long-acting pre-exposure prophylaxis. We examined whether mutations observed for DTG would emerge in vitro with CAB.
View Article and Find Full Text PDFViruses
November 2024
Center of Excellence in Clinical Virology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.
The hepatitis C virus (HCV) infection, a global health concern, can lead to chronic liver disease. The HCV core antigen (HCVcAg), a viral protein essential for replication, offers a cost-effective alternative to HCV RNA testing, particularly in resource-limited settings. This review explores the significance of HCVcAg, a key protein in the hepatitis C virus, examining its structure, function, and role in the viral life cycle.
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