Effect of Human Beta Defensin-2 in Epithelial Cell Lines Infected with Respiratory Viruses

β-defensins are a family of antimicrobial molecules involved in inflammatory processes and infections. In human airways, β-defensin-2 (hβD-2) is the best characterized in bacterial and fungal infections; however, it has been insufficiently studied in viral infections. The respiratory syncytial virus (RSV) and adenoviruses (ADV) are important agents of acute respiratory infections. The aim of this study was to measure in vitro the production and antiviral activity of hβD-2 in HEp-2 cells and A549 cells infected with ADV and RSV; hβD-2 production at different times was assessed by RT-PCR, and its presence by immunodetection assay (Western blot) using antibodies anti-hβD-2. The effect of this defensin on viral replication was determined using recombinant hβD-2 in plaque assays. The results revealed that in the cell lines production of hβD-2is up regulated after ADV or RSV infection, in direct proportion to the exposure time to each virus. The use of a high concentration of recombinant hβD-2 resulted in less deleterious viral effect on the cells. The results suggest that both viruses induce hβD-2 production, no matter if the virus is enveloped or not, and that presence of hβD-2 reduces replication and cytopathic in vitro effect of RSV and ADV. The hβD-2 production by low pathogenicity viruses or live viral vaccines can be useful as therapeutic tools in some infectious diseases.