FIG 4.

Cell binding and internalization is limiting for EV-D68 replication in neuronal cells. Replication of EV-D68 isolates following transfection of genomic RNA into (A) HeLa and (B) SH-SY5Y cells was evaluated. RNAs were purified from various HRV and EV-D68 virus stocks and used to transfect SH-SY5Y and HeLa cells. Cell culture lysates were collected at various time points and viral titer determined by TCID₅₀ in HeLa cells. Error bars represent SEM from three biological replicates. (C) EV-D68 US/MO/47, US/TN, or VR1197 virus preparations were incubated with HeLa or SH-SY5Y cells for 2 h at an MOI of 1, and virus attachment was subsequently measured by RT-qPCR. Copy number was calculated relative to a cDNA standard curve. Error bars represent SEM from three biological replicates.