Figure 4

Screen of host genes essential for an HCV infection.

(a) Primary HCVcc screening data. The count of every sgRNA is the number of reads that match the sgRNA target sequence. (b) sgRNA ranking was based on the fold change of normalised counts of every sgRNA in the HCV treated and untreated populations. (c) The FDR (false discovery rate) of every gene in the library was calculated by MAGeCK³² based on the counts and kinds of sgRNAs in the three replicates. (d) Effects of the gene knockout of CLND1, OCLN and CD81 on cell-free entry of HCVcc. All cells indicated carry the NIrD system. Light and fluorescence images were taken 72 h post-HCVcc infection in the presence of Dox (2 μg/ml). Scale bar, 100 μm. (e) Effects of the gene knockout of CLND1, OCLN and CD81 on cell-to-cell transmission of HCVcc. Huh7.5(NΙrD) cells with the indicated background (WT, CLDN1^−/−, CLDN1^−/−/CLDN1, OCLN^−/−, OCLN^−/−/OCLN, CD81^−/− or CD81^−/−/CD81) were co-cultured with HCVcc pre-infected (24 h prior) Huh7.5 cells. HCVcc carries the EGFP gene in its genome²⁸, resulting in a punctuated green fluorescence pattern in the cells. OCLN^−/− and CD81^−/− knockout cells expressed diffused green fluorescence because they were derived from cells expressing EGFP. The light and fluorescence (green and red) images were taken 72 h following the co-culturing of the cells. Scale bar, 100 μm.