(A) Cells were exposed to various MOI (5, 10 and 20 MOI) of the living PAK or ΔFliC strain for 24 h, then total mRNA was prepared and subjected to RT-qPCR using 18S as a standard. The levels of MUC5AC protein present in cell lysates (B) and in supernatants (C) were measured using an ELISA assay, as described in Materials and Methods. (D) Shows the levels of LPS in NCI-H292 supernatants after 1 h of infection with PAK or ΔFliC. (E) Shows the cells pre-treated with TLR4 inhibitor (TLR4i, 5 µM), as indicated in Material and Methods. before incubation with bacteria. The results are expressed as the percentage of inhibition of MUC5AC mRNA expression in TLR4i treated vs untreated cells. Values represent means ± SM of 3 independent experiments. *P<0.05, **P<0.01 and ***P<0.001 when comparing PBS to infected cells. C = control. & P<0.05, && P<0.01, &&& P<0.001 when comparing ΔFliC to PAK infected cells.