FIG. 6.
CatB and CatL are dispensable for mutant GPΔMuc-mediated entry, but cysteine cathepsin activity is still required. (A) Vero cells were pretreated for 4 h with 1% DMSO, 0.5 μM FYdmk, or 0.5 μM FYdmk plus 80 μM CA074. The cells were then incubated for 1.5 h with the WT, CA074R rVSV-GPΔMuc, or rVSV-G at an MOI of 0.001 FFU/cell and overlaid with agarose containing DMSO or drug. Viral titers (FFU/ml) were determined at 18 hpi. Averages ± standard deviations for three trials are shown. (B) Vero cells were pretreated for 4 h with various concentrations of E-64, then challenged with the WT, CA074R rVSV-GPΔMuc, or rVSV-G, and overlaid with agarose containing no drug. Average viral titers for two trials from a representative experiment are shown.