Inhibition by antibodies to HCV and to HVR1 of the binding of HCV in X plasma to human cell lines and platelets.
(A) X plasma (1.7 × 105 IU HCV) was incubated with various concentrations of human anti-HCV IgG or control human IgG before addition to Molt-4 cells, U937 cells, or platelets. The binding of HCV to cells was then quantitated by real-time RT-PCR analysis of HCV RNA. Data are expressed as percentage inhibition of HCV binding and are means ± SD of values from 3 to 5 independent experiments. (B) IgG from an HCV-infected patient was purified on a protein G column. Anti-X HVR1 peptide was then purified by affinity chromatography. Anti-X HVR1 (eluted fraction), the corresponding nonretained IgG fraction, and control human IgG were incubated at a concentration of 5 μg/mL with X plasma prior to addition to target cells. The binding of HCV to cells was then quantified by real-time PCR analysis of HCV RNA. Data are expressed as percentage inhibition and are means ± SD of values from 5 independent experiments.
