Potent inhibition of late stages of hepadnavirus replication by a modified cell penetrating peptide

PLoS One. 2012;7(11):e48721. doi: 10.1371/journal.pone.0048721. Epub 2012 Nov 16.

Abstract

Cationic cell-penetrating peptides (CPPs) and their lipid domain-conjugates (CatLip) are agents for the delivery of (uncharged) biologically active molecules into the cell. Using infection and transfection assays we surprisingly discovered that CatLip peptides were able to inhibit replication of Duck Hepatitis B Virus (DHBV), a reference model for human HBV. Amongst twelve CatLip peptides we identified Deca-(Arg)₈ having a particularly potent antiviral activity, leading to a drastic inhibition of viral particle secretion without detectable toxicity. Inhibition of virion secretion was correlated with a dose-dependent increase in intracellular viral DNA. Deca-(Arg)₈ peptide did neither interfere with DHBV entry, nor with formation of mature nucleocapsids nor with their travelling to the nucleus. Instead, Deca-(Arg)₈ caused envelope protein accumulation in large clusters as revealed by confocal laser scanning microscopy indicating severe structural changes of preS/S. Sucrose gradient analysis of supernatants from Deca-(Arg)₈-treated cells showed unaffected naked viral nucleocapsids release, which was concomitant with a complete arrest of virion and surface protein-containing subviral particle secretion. This is the first report showing that a CPP is able to drastically block hepadnaviral release from infected cells by altering late stages of viral morphogenesis via interference with enveloped particle formation, without affecting naked nucleocapsid egress, thus giving a view inside the mode of inhibition. Deca-(Arg)₈ may be a useful tool for elucidating the hepadnaviral secretory pathway, which is not yet fully understood. Moreover we provide the first evidence that a modified CPP displays a novel antiviral mechanism targeting another step of viral life cycle compared to what has been so far described for other enveloped viruses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Capsid / drug effects
  • Capsid / metabolism
  • Cell Line
  • Cell-Penetrating Peptides / metabolism*
  • Cell-Penetrating Peptides / pharmacology*
  • Gene Expression Regulation, Viral / drug effects
  • Hepatitis B Virus, Duck / drug effects*
  • Hepatitis B Virus, Duck / genetics
  • Hepatitis B Virus, Duck / metabolism
  • Hepatitis B Virus, Duck / physiology*
  • Humans
  • Intracellular Space / drug effects
  • Intracellular Space / virology
  • Lipid Metabolism
  • Protein Transport
  • Time Factors
  • Viral Structural Proteins / metabolism
  • Virus Replication / drug effects*

Substances

  • Cell-Penetrating Peptides
  • Viral Structural Proteins

Grants and funding

This work was supported by grants of the Agence National de la Recherche contre le SIDA (ANRS)(http://www.anrs.fr/) to MK, LC and FA and the Fondation pour la Recherche Médicale (FRM)(http://www.frm.org/) to MK and INSERM to LC. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.