FIG 1.

TLR7 agonists exhibit antiviral activity against MNV with minimal cytotoxic effects. (A) The antiviral effects of each TLR7 agonist against MNV were assessed in cell culture using a plaque reduction assay in RAW264.7 cells. Each compound was tested over eight concentrations (0.1 nM to 10 μM for R-848, 50 nM to 20 μM for imiquimod, and 10 nM to 20 μM for Gardiquimod and GS-9620) after incubation for 48 h. Plaques were enumerated and compared to those obtained in uninhibited DMSO controls to calculate the half-maximal effective concentration (EC₅₀) of each compound. (B) The cytotoxic effects of each TLR7 agonist against RAW264.7 cells were assessed at concentrations that ranged between 0.05 and 50 μM using the CellTitre-Blue assay. All compounds retained >50% viability at 25 μM. Plotted data represent the means ± SEM for two (panel B) or three (panel A) independent experiments performed in triplicate.