Figure 5.

Infectivity of r19F and r19F_CX4C viruses in pHAECs. Differentiated pHAECs from three adult donors were inoculated with RSV at multiplicity of infection of 0.1 or 0.3. the r19F or r19F_CX4C virus in PBS or PBS alone (mock), was added to the apical surface of the cells and incubated for 2 h at 37 °C. Cells were incubated for 2, 4, or 6 days at 37 °C and 5% CO₂ and then collected with trypsin-0.05% EDTA. Cells were transferred to a 96-well plate, washed, fixed, permeabilized, and blocked with PBS containing 0.5% BSA. They were then incubated with human anti RSV F monoclonal antibody followed by Alexa Fluor^® 488 labeled goat anti human IgG (H+L) antibody incubation. Labeled cells were detected by flow cytometry and results analyzed by FlowJo. Data are expressed as r19F/r19F_CX4C ratios. (A) Experiment 1. (B) Experiment 2. NHBE#1, NHBE#2, NHBE#3—primary human bronchial epithelial cultures from donors 1, 2, 3, respectively. The differences between the r19F and r19F_CX4C (ratio is given above the bar) are significant at p < 0.01 for day 2, p < 0.05 for day 4, and p < 0.01 for day 6 for mean values across all three pHAEC specimens for the two independent experiments by the paired t-test.