Priming with antiviral concentrations of TG displays no cytotoxicity in respiratory epithelial cells. (A,B) NPTr cells and (C,D) NHBE cells were incubated in indicated concentrations of TG or in DMSO control for 30 min and (A,C) cell viability assays (CellTiter-Glo luminescent cell viability assay) or (B,D) caspase 3/7 activity assays (Caspase-Glo 3/7 assay) performed 24 h later. Significance determined by one-way ANOVA, relative to DMSO control. No significant change in cell viability or caspase activity was found. (E) NHBE cells and (G) NPTr cells were incubated for 30 min in a range of TG concentrations, PBS washed and infected for 24 h with USSR H1N1 virus at 1.0 MOI and 0.5 MOI, respectively. Spun sns were used to infect MDCK cells for 6 h in FFAs. EC50 was calculated from progeny virus output (%) by non-linear regression. (F) NHBE cells and (H) NPTr cells were incubated for 30 min in a range of TG concentrations, PBS washed and cell viability assay (CellTiter-Glo luminescent cell viability assay) performed 24 h later. CC50 was calculated from relative cell viability (%) by non-linear regression. SIs (CC50/EC50) for NHBE and NPTr cells are 15,483 and 8087, respectively.