Figure 6. IL-17 and its differential effects on epithelial barrier integrity.

(a) 16HBE14o cell line was plated on electrode array chamber slides and allowed to be confluent. Upon confluence, they were treated with 0, 1, 10, 20 and 100 nM recombinant IL-17 and trans-epithelial electrical resistance (TEER; impedence) was measured in real-time to verify the effects of the cytokine on epithelial barrier. There is a clear departure of bronchial epithelial response to change in IL17 concentration; while lower doses (up to 10 nM) are protective, higher doses (20 and 100 nM) exhibit disruption in barrier integrity. (b) Wild-type (C57Bl6/j) animals (n = 5) were implanted with placebo/75 mg morphine pellets for 24 hours and PL was intrasasally administered for 0 and 3 hours. Lung sections from these animals were stained for occludin (tight-junction protein) and cytokeratin (epithelial marker) to verify the status of barrier. Fluorescence intensity of occludin was measured using ImageJ (c) and normalized with cytokeratin MFI [error bar = SD; **p < 0.01].