Differential effects of cytokines and corticosteroids on toll-like receptor 2 expression and activity in human airway epithelia.

Background: The recognition of microbial molecular patterns via toll-like receptors (TLRs) is critical for mucosal defenses.

Methods: Using well-differentiated primary cultures of human airway epithelia, we investigated the effects of exposure of the cells to cytokines (TNF-alpha and IFN-gamma) and dexamethasone (dex) on responsiveness to the TLR2/TLR1 ligand Pam3CSK4. Production of IL-8, CCL20, and airway surface liquid antimicrobial activity were used as endpoints.