Effect of Hypertonic Saline Solution on cultures of human respiratory epithelium infected by respiratory syncytial virus

Abstract

Introduction: nebulizations with hypertonic saline solution (HSS) has been incorporated in treatment of infant bronchiolitis but is currently a subject of controversy. Experimental studies on models of RSV infection have not been published.Objectives: to study the effect of HST in cultures of human respiratory epithelium infected with respiratory syncytial virus (RSV).Materials and Methods: Human respiratory epithelial cells (Hep-2 and Calu-3 lines) were cultured in monolayer. Cultures were divided into 3 groups: G1-control cells; G2-cells exposed to RSV for 3 hours, after which the culture medium was replaced by fresh medium without RSV for 72 hours; G3-cells exposed to RSV for 3 hours, after which culture medium was replaced by virus-free medium with addition of ClNA (final osmolarity, 400 m0sm) for 3 hs. Supernatant was stored and frozen for measurement of pro-inflammatory cytokines (IL-6, IL-8. ELISA). The percentage of RSV infected cells at 72 hours (flow cytometry) was determined in each group. The corresponding cell viability controls were performed (MTS-Cell Titer 96®), (Annexin V Apoptosis Detection Kit ?).Results: treatment with HSS did not alter the number of viable cells and reduced the percentage of Hep-2 and Calu-3 cells infected by RSV (68% and 40% respectively). This was associated with decrease in IL-6 and IL-8 release (p < 0.05).Conclusions: the addition of HSS decreased viral infection and pro-inflammatory response in cultures of human respiratory epithelial lines.