Antiviral activity of Bay 41-4109 on hepatitis B virus in humanized Alb-uPA/SCID mice.

Current treatments for HBV chronic carriers using interferon alpha or nucleoside analogues are not effective in all patients and may induce the emergence of HBV resistant strains. Bay 41-4109, a member of the heteroaryldihydropyrimidine family, inhibits HBV replication by destabilizing capsid assembly. The aim of this study was to determine the antiviral effect of Bay 41-4109 in a mouse model with humanized liver and the spread of active HBV. Antiviral assays of Bay 41-4109 on HepG2.2.15 cells constitutively expressing HBV, displayed an IC(50) of about 202 nM with no cell toxicity. Alb-uPA/SCID mice were transplanted with human hepatocytes and infected with HBV. Ten days post-infection, the mice were treated with Bay 41-4109 for five days. During the 30 days of follow-up, the HBV load was evaluated by quantitative PCR. At the end of treatment, decreased HBV viremia of about 1 log(10) copies/ml was observed. By contrast, increased HBV viremia of about 0.5 log(10) copies/ml was measured in the control group. Five days after the end of treatment, a rebound of HBV viremia occurred in the treated group. Furthermore, 15 days after treatment discontinuation, a similar expression of the viral capsid was evidenced in liver biopsies. Our findings demonstrate that Bay 41-4109 displayed antiviral properties against HBV in humanized Alb-uPA/SCID mice and confirm the usefulness of Alb-uPA/SCID mice for the evaluation of pharmaceutical compounds. The administration of Bay 41-4109 may constitute a new strategy for the treatment of patients in escape from standard antiviral therapy

HBV viral load in control and treated infected uPA chemeric mice.

1<p>an arbitrary threshold of detection of 100 copies/ml was used for calculation.</p>2<p>nonparamertic Mann-Whitney test.</p

Antiviral activity of Bay 41-4109 on HBV replication in HepG2.2.15 cells.

<p>Cells were treated with Bay 41-4109 (25, 50, 100, 200 and 400 nM) as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0025096#s2" target="_blank">Methods</a> section. HBV DNA in HepG2.2.15 supernatant was quantified by real-time PCR. The data represent the results of three independent experiments, performed in duplicate.</p

Immunohistological analysis of human hepatocytes in mouse livers.

<p>Serial sections of chimeric mouse livers from treated (T529 and T490) and untreated (C371) mice were analyzed by labeling with anti-α1 anti-trypsin (αAT) or with anti-HBc (HBc) antibodies.</p

Antiviral activity of Bay 41-4109 on HBV replication in humanized Alb-uPA/SCID mice.

<p>(A) Human albumin concentrations in sera from treated (full lines) and untreated (dotted lines) animals. (B) The HBV viral load during the course of the experiment was quantified by real-time PCR in sera from treated (full lines) and untreated (dotted lines) animals. (C) Histograms represent the mean HBV load ratio at specific time points in each treated (white) and untreated (black) animal. Data are represented on semilogarithmic graphs.</p