Fig. 1.

Inhibitory activity of compounds 1 and 2 on HRSV F protein expression. Diagram of the experimental setup. A) A549 cell monolayers grown in coverslips in 24-well plates (for IIF) were infected with HRSV A2 and L19 strains (moi = 0.1) and incubated for 2 h at 37 °C. The inoculum was discarded, and cells were further incubated with fresh medium or treated with 10 μM of the compounds for further 24 h. Cells were processed for an IIF to detect HRSV F protein (red), as described in Materials and Methods. Cells nuclei were stained with Dapi (blue).

Quantification of the IIF. (B) Mean fluorescence intensity of F was quantified as described in Materials and Methods. (C) The number of fluorescent cells expressing F was determined in ten different fields of the control and each treatment condition, in duplicate, and it was expressed as percentage of cells expressing F protein with respect to the total cells in the field. * Significantly different (p < 0.05), One-way ANOVA with post-hoc Tukey test.