Figure 4. IAV reduces CFTR single-channel activity in infected but not uninfected NHBEs.

NHBEs were grown on glass cover slips and infected with PR8^ΔGFP at a MOI of 6. Infected (GFP⁺) and noninfected (GFP^–) cells were patch-clamped 48 hours p.i. in the cell-attached mode, and forskolin-treated single-channel activities (CFTR) were recorded. (A) Representative CFTR single-channel activity traces recorded from an uninfected NHBE. CFTR was activated with forskolin (10 μM) and inhibited with PPQ-102 (10 μM), a CFTR inhibitor. (B) Amplitude histogram showing the distribution of active channels after forskolin addition. Channel conductance recorded at –100 mV shows a peak at about 0.6 pA corresponding to a unitary conductance of 6 pS. (C and D) CFTR activity in NHBEs infected with PR8^ΔGFP. (C) Typical recording after addition of 10 μM forskolin. (D) Forskolin activation of channel with 6 pS conductance was reduced markedly in GFP⁺ cells. (E) CFTR activity, as open probability of the channels recorded from 9 uninfected and 9 infected cells. Data were analyzed by 1-way ANOVA followed by post hoc Tukey test for multiple comparisons. Data are plotted as mean values (N = 9), top and lower quartiles ± SD. *P < 0.0001.