FIG 4.

hBD2 expression is induced by live lactobacilli in direct contact with host cells. Pharyngeal epithelial cells were incubated with live L. reuteri (L.r), L. reuteri that had been heat-killed (HK), or L. reuteri conditioned medium (CM). To separate bacteria from host cells, 0.4-μm hanging cell culture Transwell filters were used. Epithelial cells were maintained in the lower compartment, and live L. reuteri [TW (L.r)] or DMEM [TW (no bact)] were added to the upper compartment of the Transwell filters. After 6 h of incubation, the gene expression of hBD2 was quantified using qPCR. Expression was normalized against the β-actin housekeeping gene and expressed as the fold change compared to the control. Data are represented as the mean values, with error bars representing the standard deviations. The assay was performed in triplicate at least three times. Significance was tested against the control. *, P < 0.05.