Fig. 8

Inhibition of HCV infection by AH peptide analogue. a A library consisting of overlapping 18-mer peptides from the entire HCV polyprotein was screened for the ability to inhibit HCV infection in a focus reduction assay using Huh-7.5.1 cells. The peptide from the N-terminal region of NS5A displayed the strongest inhibition. b Determination of peptide concentration required to inhibit HCV infection by 50% (IC₅₀). Peptide stock solutions were serially diluted in DMSO and tested for inhibitory activity. Peptide cytotoxic activity was measured MTT cytotoxicity assay. The peptide concentration that reduced the cell growth by 50% was designated as the LC₅₀. c AH peptide analogue prevents initiation of HCV infection and suppresses established infection. Fifteen days after infection of Huh-7 cells, the l- and d-isomers of the AH peptide analogue were added. At the indicated time points, total cellular HCV RNA content was measured. For comparison, the infected cells were treated with 100 U/mL of recombinant human IFNα. d AH peptide analogue inhibits intracellular HCV particle infectivity. To determine whether the peptide enters cells, a fluorescently labeled version was incubated with Huh-7 cells, and analyzed by confocal fluorescence microscopy. e Huh-7 cells previously infected with HCV were treated with d-isomers of AH peptide analogue or DMSO. After 6 h, intracellular HCV infectivity was determined. Figure is adapted and modified from Ref. [45]