Fig. 2

Involvement of Toll-like receptor 3 (TLR3) in influenza A virus (IAV)-mediated cilia-driven flow and ciliary beating orientation. TLR3-KO murine tracheal epithelia were incubated for 1 h with or without IAV in the culture medium, and then cilia-driven flow and ciliary beating orientation were evaluated. a Representative beads trajectories of cilia-driven flow (rainbow trace for 4.4 s). b and c Both the histogram (b) and bar chart (c) of cilia-driven flow demonstrated that IAV infection had no impact of cilia-driven flow in TLR-3KO culture (Ctrl, 7.51 ± 0.35 µm/s; IAV, 8.28 ± 0.30 µm/s; n = 150 beads in each condition). d Kymograph of ciliary beating with or without IAV infection. e IAV infection did not affect ciliary beat frequency (CBF) in TLR3-KO culture (Ctrl, 17.58 [12.89–21.09] Hz; IAV, 18.75 [14.06–23.44] Hz; n = 30 in each condition). f Amplitude of ciliary beating was similar between the two conditions (Ctrl, 6.59 ± 0.41 µm; IAV, 6.48 ± 0.35 µm). g and h The effective stroke velocity (g) (Ctrl, 343.6 ± 26.5 µm/s; IAV, 357.3 ± 17.1 µm/s) and recovery stroke velocity (h) (Ctrl, 296.9 ± 19.9 µm/s; IAV, 298.2 ± 21.9 µm/s) did not differ between the groups. i The ratio of the effective stroke velocity to recovery stroke velocity was not different between the two conditions (Ctrl, 1.21 ± 0.07; IAV, 1.26 ± 0.08). Ctrl control, ns not significant; CBF data were presented as the median (range)