Figure 4.

SAs removal does not affect HCoV-OC43 VR-1558, BCoV, or CRCoV replication. Cells pretreated with type II neuraminidase (NA, 200 mU/mL) were overlaid with HCoV-OC43 VR-1558, BCoV and CRCoV stocks (at TCID₅₀ of 400 per milliliter, which approximately corresponds to M.O.I. = 0.0007) and incubated for 2 h at optimal temperature (see Viral stocks). Subsequently unbound virions were washed off and the cells were further incubated at optimal temperature for five days. (A) virus yield assessed by RT-qPCR. (B) NA effect on cell viability, as determined by an XTT assay. (C) The proportion of infected cells in the whole population normalized to control (flow cytometry). All data is presented as mean ± SD from at least three experiments in triplicate. (* p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0.0001).