Rhinoviruses induce interleukin-8 mRNA and protein production in human monocytes.

Rhinoviruses are important upper respiratory pathogens that are strongly associated with asthma exacerbations. However, the inflammatory response to rhinovirus infection is poorly understood. Interleukin (IL)-8 has been implicated in the pathogenesis of respiratory viral infections and asthma. Rhinovirus-induced IL-8 release and mRNA induction were examined in peripheral blood mononuclear cells (PBMC). Rhinoviruses induced IL-8 release for up to 7 days after inoculation onto PBMC. This was associated with an increase in IL-8 mRNA expression that peaked 48 h after exposure to the virus. IL-8 protein production was reduced by UV inactivation of the virus and abolished by preventing virus-receptor binding. Although rhinovirus replication was not demonstrated in PBMC, low-grade productive infection was shown in the human monocyte cell line THP-1. Rhinovirus induction of IL-8 in monocytes or airway macrophages may be important in the pathogenesis of rhinovirus-induced asthma exacerbation.