Gene Expression Signature-Based Screening Identifies New Broadly Effective Influenza A Antivirals
Figure 6
Antiviral effects of most of the molecules are due to an action on cells rather than on the virus.
In the ‘Cell Preincubation’ assay, A549 cells were treated with increasing concentrations of the molecules or solvent for 14 h and washed twice before incubation with H3N2 influenza A virus at an moi of 7 during 15 min and infection for 5 h in medium without drug. In the ‘Virus Preincubation’ assay, H3N2 viral stock was treated with increasing concentrations of molecules or solvent for 14 h and diluted 12 times before incubation with cells during 5 min and infection for 5 h. In both assays, the number of infected cells was estimated with a neuraminidase test after cell lysis with Triton 1X. The normalized infection efficiency was calculated as RFU in treated cells/RFU in control cells. Values represent the mean of two independent experiments (+/− standard deviation). Results of the preincubated cell test are plotted with colored dots and results of the virus preincubated assay are depicted with grey bars. * and # indicate statistically significant differences of infection efficiency in comparison to untreated control cells (Welch two-sample t test, pvalue <0.05), for the preincubated cell test and for the preincubated virus test, respectively.