Fig. 3.

Effect of compounds 1 and 2 on HRSV entry into the cells. Diagram of the experimental setup. A). Refractory effect to infection. A549 cell monolayers were treated with compounds 1 and 2 during 24 h before infection. Then, the compounds were removed, and cells were washed 3 times and they were infected with HRSV. After 24 h virus yields were collected and titrated by plaque assay in Vero cells. B). Effect of the compounds on virus adsorption to the cells. A549 cell monolayers were infected with HRSV (moi = 1) together with 20 μM and 40 μM of the compounds, and incubated for 2 h at 4 °C. The inoculum was discarded, and cells were washed, supplemented with fresh culture media, and further incubated for 24 h at 37 °C. Virus yields were collected and titrated by plaque assay in Vero cells. C). Effect of the compounds on virus internalization. A549 cell monolayers were infected with HRSV (moi = 1) and incubated for 2 h at 4 °C. The inoculum was discarded, and cells were washed and treated with 20 μM and 40 μM of the compounds for 15 min and 1 h at 37 °C. Afterwards, cells were washed, and non-internalized virus was inactivated with citrate buffer (pH 3) for 1 min. Cells were further incubated with fresh culture media for 24 h at 37 °C. Virus yields were collected and titrated by plaque assay in Vero cells. Data represent mean ± SD for 3 independent experiments, performed in duplicate.

One-way ANOVA with post-hoc Tukey test. No significant differences were found.