Levocetirizine inhibits rhinovirus-induced ICAM-1 and cytokine expression and viral replication in airway epithelial cells.

Levocetirizine inhibits the production of intercellular adhesion molecule (ICAM)-1 and secretion of interleukin (IL)-6 and IL-8, which may have beneficial effects on the pathophysiologic changes related to human rhinovirus (HRV) infection. We investigated the effects of levocetirizine on rhinovirus infection in primary human nasal epithelial cells (HNEC) and A549 cells. Cells were treated with different concentrations of levocetirizine, ranging from 0.5, 5 or 50nM, either starting at the time of infection and continuing thereafter, or beginning 24h before infection and continuing thereafter. Levocetirizine treatment inhibited the HRV-induced increase in ICAM-1 mRNA and protein levels, as well as the HRV-induced expression of IL-6 and IL-8 mRNA and protein levels. Viral titer, as measured by culture in MRC-5 cells, was reduced by levocetirizine. Levocetirizine treatment also reduced the increased nuclear factor-kappa B (NF-kappaB) expression seen with HRV infection. Levocetirizine inhibited the expression of Toll-like receptor (TLR)3 mRNA and protein levels. These findings indicate that, in HNEC and A549 cells, levocetirizine inhibits HRV replication and HRV-induced upregulation of ICAM-1, IL-6, and IL-8, TLR3 expression and NF-kappaB activation. The results of this study suggest that levocetirizine may have a possible clinical application in the treatment of airway inflammation caused by HRV infection.