Effect of co-culturing human primary basic fibroblasts with respiratory syncytial virus-infected 16-HBE cells.

This study investigated the effects induced by co-culturing human primary basic fibroblasts (HPBFs) with 16-human bronchial epithelial cells (16-HBE) infected with respiratory syncytial virus (RSV), in particular the transformation of HPBFs into myofibroblasts and secretion of extracellular matrix proteins. HPBFs were co-cultured with 16-HBE cells infected with RSV and quantitatively analyzed. We constructed models of HPBFs co-cultured with 16-HBE cells that were either uninfected (control group) or infected with RSV (experimental group). Following initiation of co-cultures, HPBFs and supernatants were collected at 24-h intervals up to 120 h. Expression of α-smooth muscle actin (α-SMA) was detected by indirect immunofluorescence and western blotting, while type I collagen (Col I) and fibronectin were analyzed by competitive enzyme-linked immunosorbent assays. After 72 h, α-SMA expression increased in HPBFs cultured with RSV-infected 16-HBE relative to uninfected controls, reaching its highest level at 96 h. Similarly, Col I secretion was also higher in HPBFs co-cultured with RSV-infected 16-HBE relative to uninfected controls; Col I secretion increased with time and reached its highest level at 120 h. HPBFs were transformed into myofibroblasts following co-culture with RSV-infected 16-HBE, which when combined with the observed increase in Col I secretion suggests that airway remodeling would then be promoted.