Grifﬁthsin Has Antiviral Activity against Hepatitis C Virus (cid:1)

Hepatitis C virus (HCV)-infected patients undergoing liver transplantation universally experience rapid reinfection of their new liver graft. Current treatment protocols do not prevent graft reinfection and, in addition, an accelerated disease progression is observed. In the present study, we have evaluated a novel strategy to prevent HCV infection using a lectin, grifﬁthsin (GRFT) that speciﬁcally binds N-linked high-mannose oligosaccharides that are present on the viral envelope. The antiviral effect of GRFT was evaluated in vitro using the HCV pseudoparticle (HCVpp) and HCV cell culture (HCVcc) systems. We show here that preincubation of HCVpp and HCVcc with GRFT prevents infection of Huh-7 hepatoma cells. Furthermore, GRFT interferes with direct cell-to-cell transmission of HCV. GRFT acts at an early phase of the viral life cycle by interfering in a genotype-independent fashion with the interaction between the viral envelope proteins and the viral receptor CD81. The capacity of GRFT to prevent infection in vivo was evaluated using uPA (cid:1) / -SCID mice (uPA stands for urokinase-type plasminogen activator) that harbor human primary hepatocytes in their liver (chimeric mice). In this proof-of-concept trial, we demonstrated that GRFT can mitigate HCV infection of chimeric mice. Treated animals that did become infected demonstrated a considerable delay in the kinetics of the viral infection. Our data demonstrate that GRFT can prevent HCV infection in vitro and mitigate HCV infection in vivo . GRFT treatment of chronically infected HCV patients undergoing liver transplantation may be a suitable strategy to prevent infection of the liver allograft. BD Biosciences, Erembodegem, Belgium). To evaluate successful engraftment in the mouse liver, the amount of human albumin present in mouse plasma was quantiﬁed by enzyme-linked immunosorbent assay (ELISA) (Bethyl Laboratories, Montgomery, TX). All animals used in this study had human albumin plasma levels of at least 2.1 mg/ml. GRFT WT or GRFT MUT was admin-istered daily via subcutaneous injection at a dose of 5 mg/kg of body weight. The GRFT treatment was started 3 days before the mice were challenged with 10 5 IU of H77 virus (3) and was continued until day 2 (2 mice), day 7 (2 mice), or day 14 (2 mice) postinfection. The animals were bled at weekly intervals, and HCV RNA was quantiﬁed using the COBAS Ampliprep/COBAS TaqMan HCV test (Roche Diagnostics, Vilvoorde, Belgium). All animal experiments were approved by the Animal Ethics Committee of Ghent University. Graphs and statistics. All graphs were prepared using Prism v5.0c (GraphPad Software Inc., La Jolla, CA). Fifty percent inhibitory concentration (IC 50 ) and 90% inhibitory concentration (IC 90 ) values were calculated via nonlinear regression analysis using a variable-slope log (dose)-versus-response curve with a least- squares (ordinary) ﬁt. To analyze whether the difference between treatment groups was statistically signiﬁcant, the data obtained from in vitro and in vivo experiments were analyzed using the unpaired nonparametric two-tailed Mann-Whitney test. Data were analyzed using GraphPad InStat v3.0b (GraphPad Software Inc.).