FIG. 2.

Lipopeptides induce inflammatory response in human respiratory epithelial cells. (A) Lipopeptides induce NF-κB activation in primary human bronchial epithelial cells. NHBEs were transfected with an NF-κB-responsive luciferase construct and incubated for 6 h in the presence of 1 μg of LPS/ml, 20 ng of TNF-α/ml, or 5 μg of lipopeptide/ml. The data were normalized to a cotransfected β-galactosidase construct. sBLP, synthetic bacterial lipopeptide (Pam₃Cys-SKKKK-OH); LPTA(6), N terminus of lptA gene product (Pam₃Cys-DKKEE-OH); LPTB(6), N terminus of lptB gene product (Pam₃Cys-DSQTN-OH). (B) Western blot analysis of TLR2 protein expression in CF (IB3-1) and CFTR-corrected (C38) cells with an anti-hTLR2 monoclonal antibody (IMG-319), detected as an 86-kDa band. Equal amounts of proteins were loaded. A densitometry analysis of the TLR2 protein was performed for three independent experiments with NIH Image 1.62 software. The numbers underneath the gel represent the means ± standard errors (arbitrary density units). (C) NF-κB luciferase assay with primary NHBEs showing that TLR2 activates the LPTA(6)-induced response in epithelial cells by employing DN-TLR2. *, P < 0.05; **, P < 0.01.