Border Control in Hepatitis C Virus Infection: Inhibiting Viral Entry

A new era has begun in the treatment of hepatitis C virus (HCV) infection with powerful yet expensive therapies. New treatments are emerging that target the entry step of HCV and could potentially block reinfection after liver transplant. These treatments include antibodies, which target the virus or host receptors required by HCV. Additionally, several new and previously approved small-molecule compounds have been described that target unique aspects of HCV entry. Overall, the blocking entry represents an attractive strategy that could yield powerful combination therapies to combat HCV

Genes induced during the clearance phase of self-limited infection.

a<p>Expression levels of genes induced above the confidence interval at week 13 but below the confidence interval at weeks 4, 6 & 40 of X0190.</p><p>The bold and italicized values represent data above the 99% confidence interval as described in the text.</p

Real-time PCR quantification of candidate genes involved in viral clearance and persistence.

<p>TaqMan real-time PCR was performed as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0003442#s4" target="_blank">Materials and Methods</a>. The y-axis shows the relative unit of a given gene normalized to GAPDH and 18s rRNA. Data are expressed as means±SEM. In all cases, average values obtained during the first eight weeks of infection were compared between recovered (X0190) and chronically infected chimpanzees (X 0234, X0142 and X6412). * <i>P<0.05</i>, ** <i>P<0.01</i>, *** <i>P<0.01</i>, **** <i>P<0.005</i>.</p

Genes induced during the early phase of self-limited and persistent infections.

a<p>Expression levels of genes induced above the confidence interval at weeks 4 & 6 but below the confidence interval at weeks 13 & 40 in X0190.</p><p>The bold and italicized values represent data above the 99% confidence interval as described in the text.</p

Effects of cell culture-adapted mutations on virus propagation.

<p>(A) One million cells were transfected with 2 µg of <i>in vitro</i>-transcribed RNA from JFH-1/wt, JFH-1/T416N, JFH-1/K1122R, JFH-1/L2525F and JFH-1/3mut. HCV propagation was monitored by measuring HCV core Ag. (B) The same amounts of JFH-1/wt, JFH-1/T416N, JFH-1/K1122R, JFH-1/L2525F, JFH-1/3mut and JFH-1/day25 viruses were used for infection of naïve Huh-7.5.1 cells (MOI  = 1.0), and HCV RNA titers were subsequently monitored.</p

Assessment of T416N on infection step by HCVpp and HCVtcp.

<p>(A) Infectivity of JFH-1/wt and JFH-1/T416N with HCVpp envelopes was assessed. Luciferase activity was measured in HCVpp-infected cells. *<i>p</i><0.05. (B) Infectivity of HCVtcp with the structural regions of JFH-1/wt and JFH-1/T416N was assessed. Luciferase activity was measured in HCVtcp-infected cells. *<i>p</i><0.05.</p

Genes induced during the early phase of self-limited infection as defined by average expression values.

a<p>Average expression values of biopsies taken during the 1^st 8 weeks of infection.</p><p>Bold-face genes are also in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0003442#pone-0003442-t001" target="_blank">Table 1</a>.</p

Iodixanol density gradient analysis of JFH-1/wt and JFH-1/T416N.

<p>Huh7.5.1 cells were transfected with full-length RNAs of JFH-1/wt and JFH-1/T416N. Culture medium of each strain was collected and analyzed by 10%–40% of iodixinol density gradient. Fractions were collected, and HCV core Ag and infectivity titers JFH-1/wt (A) JFH-1/T416N (B) were measured.</p

Mutations Detected in Cell Culture-adapted JFH-1 Variants.

a<p>‘−’ means synonymous mutation.</p

Iodixanol density gradient analysis of JFH-1/2G and JFH-1/6B.

<p>Huh7.5.1 cells were transfected with full-length RNAs of JFH-1/2G and JFH-1/6B. Culture medium of each strain was collected and analyzed by 10%–40% of iodixinol density gradient. Fractions were collected, and HCV core Ag and infectivity titers of JFH-1/2G (A) and JFH-1/6B (B) were measured.</p